Brakes Tests 5 and 6 Power Brakes and Park Brakes

alright that’s not surprising all right breaks test five breaks test five the two basic types of break power boosters or vacuum assisted and electronic assistant is that true or is that false okay for whaling do you think have you ever seen any electronic brake power boosters huh can you have electronically power booster brakes what what Jesus don’t that back yeah which one diesels don’t but they don’t use electronic I haven’t either that’s why this question is false ah what a diesel diesel embrace right they actually know they’ve got a power brake pretty sure that does it you got it calibrate crashing yeah power brake fluid sins pressure to the power brake booster it is a hydraulic as a hydro boost you probably I let all those Humvees probably got hydraulically assisted power brakes a little right man yeah listen that’s typically with that kind of thing goes ok how’s getting ready to show you guys a picture a minute whenever just appeared was thinking okay I’m as ferric pressure acting on the pedal side of a booster diaphragm results in boosting pressure to the master sellers primary piston atmospheric pressure acting on the pedal side of a booster diaphragm results in boosted pressure to the master cylinders primary piston professor you’re actually know which outlet pressure is helping you do it we’re talking to power brakes here okay so what you’re going to do is when you hit your brake pedal ullu a spool valve in there and basically it causes the evidence it’s basically cuz it’s opening up a bit and it lets atmospheric pressure come into that booster and is pushing on the back is tougher there is a reason why that diaphragm is this big around because you want a lot of square inches for this 14 and a half pounds requiring to push against wines got vacuum it’s got vacuum on both sides until you hit the brake and then it shuts off the vacuum to the back side and atmospheric pressure comes in there and it helps you apply the brake you got me so and that’s what the new is it actually can want it will come to a place you know the spool valve basically and I showed you that all very first day do you remember that those slides we went through all the power brake booster that’s what this is talking about so on the pedal side of it if that Matt misheard pressure is actually was doing that because what’s causing things to move is not vacuum it’s pressure pressure is what causes things to move so what is vacuum absence of pressures so what is cold yes exactly so basically what you’re talking about the absence of you know vacuum is not a tangible thing it’s the absence of something else maybe if that makes any sense okay brakes will no longer work after all the vacuum has been used true or false do you know how stupid it would lead it as an that that way I mean do you know okay you’re basically going to have regular breaks whenever if your power brakes fail hydraulic boost is constant even if the engine is under lewd well actually that’s true that’s true you can assign values yeah it’s under like boosting her if his engines running you got hydraulic pressure and if engines under load it’s obviously running in a Power Master booster the power steering fluid can be added to the master cylinder reservoir with no ill effects now whatever but power steering fluid in the master cylinder but that will slow all the rubber up and everything had to be rebuilt if you’re having it done somewhere really charged you it’s like several thousand dollars so always but only brake fluid in the brake booster I mean in the master cylinder yeah you don’t put anything in the brake booster you’re going to use power steering fluid from your that system when testing a hydraulic pressure storage system final break signing a brake pedal is hard to push on the first application means the accumulator is leaking and that is true that is true in order for their vacuum boosters to operate vehicles with diesel engines need a separate pump for their vacuum supply that’s right it’s true if they have a vacuum booster they’ve got a little vacuum pump and it’s got a pulley on it that looks like a power steering pulley now remember what I told you about your pulley sizes your power steering pulley is a big pulley your alternator plays a little pulling there’s a reason why those points are those sizes right so you need to have be able to produce a couple thousand pounds of pressure on these power steering system so you’re a pretty good-sized

bullion there air conditioning is hard to pull you know because you’re operating a compressor you got big pulley so if it’s hard to pull you’re going to have a big pulley and the speed of it is basically something else to like on a water pump you know the water pump is going to take a little effort turn not a ton of effort but it’s going to take some effort it won’t be as hard to pull as the power steering pump but you’re won’t knitting out to spend really really fast because you don’t want it cavitating and making air bubbles and whipping up phone so basically the size of it is more related to water pump to to the speed of it than it is the power is needed ok adding power steering excuse me the brake pedal ratio is the ratio of the lengths of the arm lever arms all the brake pedal assembly we don’t ever think about that it’s not even an important question but it is true adding power steering fluid to the master brake cylinder is a very dangerous mistake that could lead to total brake failure it won’t typically lead to brake failure but what it will cause them to do I’m telling you it calls the brakes to lock up and not come loose I mean that’s usually what happens it’ll get to work it’s holding the brakes all the time and it’s slowly to slower and slower and slower and it gets where you can even go because it breaks our old huh yes you can call that so that is actually going to be true in 10 the power piston is the interface between the front push rod and the master cylinder that’s false he just uses guessing out of air about that a tandem now from booster excuse me tandem now from a vacuum booster has one diaphragm instead of two that sound of tandem is talking about to I’m right okay number 12 power boosters are mounted where come over y’all will be done between the back pedal liver in the master juggler yeah that’s a seat to multiply the force coming from the brake pedal vacuum boosters are allowed what I think you’re fragile yes a pressure differential across the diaphragm number 14 an undesirable hissing noise caused by air rushing into the chambers of a vacuum booster is prevented by means of what you guys are really funny it’s a filter have you looked at that little has a little accordion boot that’s right up there that’s around that I mean it’s coming out at booster metal accordion Buddha’s got some little fibrous filter looking stuff showing through the lolz you know mean and what happens is when that air goes through that has to go through those little filters and it neutralizes that sound how many of you guys have ever driven a vehicle for a long time that had no power brakes but if it is wonderful have to imagine that break that word it really muscles up that legs on it sometimes you got to you both like you dare to do you you know you drove a little bit no brakes did you for a while right there number 15 all of the following or advantages of a tandem diaphragm booster except what be doubling of surface area provides improved gas mileage please that’s wrong that’s an accept that this is like an ASC question your ocsc questions it says all of the above are correct except you know to prevent fluctuating manifold pressures from affecting the amount of vacuum available from the booster vacuum is often stored in a white man anybody else got any ideas reservoir reservoir now we used to have those some of these vehicles the cruise control was vacuum operated and whenever you were going up a hill your cruise control was applied the throttle what was happening to the vacuum it was going away because he reloaded when you vacuum goes away when the engines loaded ok so when you were going up a hill with cruise control on he would basically cut its own throat because it was requiring vacuum and operating the vacuum operated cruise control but the more he went into the throttle the less vacuum you’ve had and the less of cruise control would work and there was a kit to fix that and have you ever looked under the hood of an older car and seen a can over there mounted on the fender that looked like a high seed drink and that’s a vacuum Risen one it’s a cheap vacuum of the work miss gossip no and that’s what we would put on there we put one of those on there and add a little check valve bill to the top so that it’s stored muscle vacuum to make things happen anytime you see a vacuum reservoir is there to combat the loss of vacuum when you’re deep into elude on an air conditioning system moody when you’re deep into the throttle and the air

conditioner dumps into the defrost you need to go looking for a vacuum leak in your AC control lines or in the AC reservoir out there under the hood or in the little one way valve that you know goes to that vacuum reservoir so just keep that in mind he’s going to default to defrost when there’s no vacuum if it’s in defrost all the time you look you’ll probably find a vacuum hose I’ll hook hood somewhere yummy alright in a hydraulic booster boost pressure is obtained from what without hearing on the power steering pump we talked about that earlier and but we have deer in the headlights people sitting around here to isolate the cause of vacuum not being stored in temecula respect all the following except one the spool valve for sticking how can you get to the dead gum spool valve ain’t no way Harry yeah but be careful when you’re taking apart a big diaphragm of any kind of like that because a lot of times there’s big springs in them they could take your head off if you’re not careful you know power brake booster not so much but some of those sexy babes bruises on truck incidentally I was going to tell you one day and this is a go instance got to do what we’re talking about it so it’s not just a funny story i was at the ford dealership and I walked by these guys in the new car department they were working on a vehicle that whenever you would give it the gas here we go it was whistled it was a brand-new vehicle got off the new vehicle lot and this guy was going to buy it if they could get that fixed before quitting time and when you crack to throttle it sounded like it was whistling past a bad throttle body gasket or something and they put a throttle body gasket on it that they had to make because of the parts room didn’t I don’t know why when I pulled it apart they didn’t notice there’s nothing wrong with his throttle body gasket is there was they were so sure it was related to the throttle and they just you know replace to throw money gasket and so I walked brother and I got interested in that you walk past the jump somebody else is doing just get interested in it oh I mean when they’re troubleshooting it and I’m not talking about just because you’re tired of pulling the transmission out of your information you’re going up somebody tires but what I mean is I got a Walkman I got a piece of hose it was late on a bench or where I put it up to my ear and I started listening for this noise can that little check valve on the brake booster was cracked and a curved way so you couldn’t see it and whenever it was it wasn’t loud at the throttle body but as i vectored in on it i found it over there at that booster there’s your problem right there I’ll pulling it out and we got another one of those that we got from somewhere I know where it came from other truckers on popped it in there that was all gone and yeah and they made the sale and the sales manager came to give me ten bucks to buy lunch the next day man you didn’t have to stop and help with that but I appreciate that you did any time that you take that attitude that you want to you know make things better for other people it’s good as long as you’re not helping them and cutting your own throat because if you’re getting paid Commission and you’re over here trying to get your work out and you stop on yours just because you’re interested and you burn an hour or helping these people you lost an hour of your own money you got me so really be careful about that sometimes you’re going to need to help them a little bit but this hogwash about come over here to help me find this bolt that I lost i don’t know time for that you know what I’m saying I mean this is something you can do you know what I mean you get a mirror in a light you find that boulders rocking to reveal off also if you drop a socket that may cost you two or three dollars to replace don’t spend twenty dollars worth of time looking for it just wrap the Dern thing off and get you another socket for me got it all right now then some people just get sick about that though the King’s dead and i’m just about one of them all right which I one of the following steps is done first when testing vacuum booster operation in other words if somebody says I want to know if the booster is working that’s going to be B you’re going to turn off the engines right the first thing you’re gonna do is turn off the engine then you’re going to pump the brake and until you’re sure there’s no vacuum store it anywhere and then you’re going to put your foot on the brake and if you’ve got a working brake vacuum booster how’s that brake pedal going to feel when you started it’s going to go down it’s going to start out stiff and it’s going to go down now how many of you have ever been bleeding brakes and you bled the brakes and you bled the brakes that when you got through you swear that thing was perfect but when you crank it up it goes to the floor you got no brakes you ever had that bed early sort of stinks that’s why in some cases it’s a good idea to bleed the brakes with the engine running this so you’ll lower the pedal rat okay and you got to know when the pedal rap though because the other day we got to situate with a couple of people killing themselves trying to bleed brakes and when I went and checked whenever they you know walked away from in it they were done and they didn’t know it yeah I mean they were done they were completely done and I come he says how does the pedal feel the guy sitting near the air-conditioning says oh it still don’t

feel good and the guy back here there was sweating bullets trying to bleed the brakes are you sure and then I went and fell seven that pedal felt like a new car okay which of the following steps is done last when testing vacuum booster operation evaluate the amount of movement in the brake pedal that’s last sweetie got it all right now yeah let’s move on to test six we got that we make it through early enough to where you can go back out on the shop at work another 30 minutes but for lunch when you like that I’m hoping mostly our floor we drive over through where we get our tuning up most parking brakes and we’re talking about parking brakes is it breaks test six most parking brakes are you use a separate set of brakes that are a plan independently of the service breaks through okay that’s most parking brakes on what would be the exception to that see this race they don’t have that hat exactly that’s what he that’s what I was thinking cuz the disc the parking brakes are always on the rear wheels rent why don’t we call a parking brake set set of emergency brakes they’re not usually adequate to stop the car in an emergency now if you’re like me and your other brakes failed you’re going to be grabbing that brake handle and trying to stop do everything you can to stop veterans twice in my life I’m hits the brakes and felt the pedal go to the floor because of brake line ruptured let me tell you about those brake lines going to the back let’s go ahead and lay it up in the frame rail on these trucks that have dirt in them because Moody’s been four wheelin they had actually traps water right up in there around that steel brake line and it slowly erodes it away and then one day when you go to hit it it’ll be like stepping on a plum to quote CW mccall a little ball into the floor and you’ll hear will see brake fluid dripping from becker you know somewhere near the back wheel and you go up in there and you’ll find out that it’s been laying in dirt and mud and moisture has been up in there and it has it rotted that brake light away so make darn sure whenever you’re coming back after a mud incident that you watch the inside of it frame rail I get all that mud out there I was driving a Volkswagen rabbits used to have the brake line run it under the carpet and that was kind of silly you know usually bless their hearts those Germans are smarter than that when it comes to mechanical stuff they pretty good about doing mechanical stuff and those Germans are they’re really good and I had the brakes on that thing at the ross clark circle down there i was going i was working at blondies no way i hit the brake and I heard something under the carpet that you know scared me silly because I was about to go out in front of a semi you know but I mean this this stuff is a serious business and just because you don’t know anybody that has ever experienced brake failure doesn’t mean you’ll never meet anybody if it’s one of your customers and you should have caught it you see all right anytime you’re looking at buying an old pickup always think about those brake lines you know what I mean one time my dad bought a car sight unseen for 50 bucks from a couple of soldiers they said we’re tired of fooling with this at something front of Josie Jones will say so again 50 bucks when I better put the car back on it drove it back to the shop and it was a ratty old thing had flowers painted all over an old Volkswagen Beetle about a 64 model or something and so we had a two-barrel carburetor on it all that stuff they’ve been trying to a little bit and so I was driving this thing wasn’t familiar where the gardens drive around me and this guy is we were really gentlemen because the only thing the back seat head back there was a board and we had this girl sitting in the back of the board you knows you just sitting on board this guy we were sick helping to come from front seat I was coming down to an intersection and he says there’s a stop sign up here and I said I knows on College Street or enterprise and when I hit the brake it suddenly went to the floor and there was two vehicles coming that are 20 feet apart and I went between them and that was scary as all get-out all I could see was that truck i was about to run into the side of it then he was gone I went across and us on the corner everywhere that’s how quick that happened but that was good brakes one application no breaks the next and that can lead to disaster it was funny that day but every one of us got a little white hair you know this kind of me you make your hair stand up okay hon I get off on all that to avoid putting stress undue stress on the park brake cable it’s best to press and hold the service brake pedal and then apply the park brake that is true but who on earth has ever done that if you done it leave it to London good grief well I haven’t done it on purpose my fiancé’s car when I heard she stopped and rolled back a little bit and then when you put it in gear at seven here here so I was old brake put it part in and hit me verse or the parking brake and that way whenever you take it off

put in tears yeah you give learn you’ve got to work around and that’s smart you know figure something out like that let’s see ideally you should use the park brake as little as possible to be sure the mechanism up raised correctly when you do need to use it that’s false I tell you what did happen though I drove that 95 Taurus and never used the park brake ever for any cuz I put it in park why don’t they depart break you know any control when its embargo you know and so one day I had the students put an air conditioner compressor on it and that was here I mean every word here at the time they put an air conditioner compressor on and they got it Park it was a conscientious son of a gun every time he parked any car you lock that park brake hard it always work well unbeknownst to me because I had been using it the red brake light didn’t work and so I got in that thing and drove it all the way to enterprise with the park brake home and when I would come up to tart and pans down there when we hit the brake I didn’t have hardly any brakes on out realized that the back brake the park brake was on in the back the brake fluid was boiling all of those back brakes like every build up the back brakes you know but uh my goodness one time I live drover car because the park brake didn’t work at good on it was nearly a new car all the way to her parents house down there and she called me and she says I drove all the way to mom and daddys house with the park break on what we need to do with us as well as it still stopped she says oh yeah that’s a well then we’ll rebuild the rear bricks if we need to just drive it over mara and I used to give somebody our damn you know said the person that gives people are Jamal huh all right okay let’s see the rotor of an auxiliary parking brake on a caliper system is shaped like a hat that’s true sometime but not every time that 4,500 out there doesn’t have a hat it’s got that silly little ball and dimple thing that you got to screw the thing back in you’ve had to do that on them on does any they got that kind I don’t know oh good fall a dimple town where you got a screw the caliber there oh yeah if you get used to that at any big deal the small breaks use of an auxiliary parking brake tend to wear out easily even with proper use that’s false but I’m going to tell you something y’all every time you get a brick job where you doing all the brakes on a you know turn of the century chevrolet that’s got the hat and it’s got a one-piece circular parking brake shoe then you better go in there and look at that park brake you because it’s probably worn out y’all probably sell a lot of them don’t you well they sell them all the time in advance i got them on the shelf but we replace them no you had to replace it when we did to break some of these college trucks but that thing wears out a lot I don’t know when but it’s worn out yeah hard to change I mean they’re easy they’re easy to change their easier than the ones they are fighting with the other day who was fighting with park bricks oh that was on Saunders car yeah or let’s see only hand activated parking brake choose a ratchet mechanism as false failure of a parking brake to release is often due to a corroded cable that’s true we worked on that Ranger in here one time where that guy had been driving it through creeks and stuff and wow that was a mess and it will cause you issue is trying to get the brakes to work right and all that especially if somebody has matched the park brake and the cables go out and they won’t go back through so we had about park brake cables for that thing put them on there and everything was rusted out on that truck we have to replace the brake part of the brake lines and I mean was terrible big job all of the following our components of a parking brake system except what yeah hydraulic tubing does not work with parking brake system unless it’s one of those Michael brake lock systems where you put it in between a brake pedal and the brakes and you flip a lever and you pump the brakes and it holds the hydraulic pressure that’s all a big truck stuff and industrial applications I’ve put those on the floor which system of parking brakes uses the same brake shoes or pads as a service grapes which system of park which parking brake system i should say uses the same brake shoes or pads as the service brakes integral parking brakes how many of you have ever seen a big brake drum on the drive shaft wrap my head of the transmission and it’s the parking brake usually on 10 and a half trucks they’ll have a great big brake drum with brake shoes in it and you pull a lever and it applies the brakes using it stops the drive shaft from turn it and that’s how the park brake set up on those big that’s okay as long as the drive shafts in it if a brake warning light stays on when the parking brake hand lever or pedal is not applied you should do flat both a and B verify the lever or pedal is returning fully to the release position check the switch at the parking brake hand lever or pedal now how many of you know that on a lot of cars when

you turn this thing to start it does approve out all some of the warning lights if that part if that cognition switch and will sum of the forces that were in the 90s you know 90s vintage sports when you turn that thing to start it may stick not far enough to keep the starter engaged but far enough to be passed the own position and some of those warning last spurt will stay on the bowler won’t work and all this until you click it back to the on position so if you see a brake light is staying on make sure that ignition switch is returning okay be careful though when you buy replacement ignition switches from the parts store because we had one that burned up that little brown wire that feeds all of those warning light proved out we turned it on in the smoke came out of that thing many sent all of them are like kappa the one we bought was that’s the three basic types of mechanisms used to mechanically actuated rear disc integral parking blakes include all the following except which one yeah recirculating ball is where where do we find recirculating balls thats in this those steering boxes like we got out there on the bench of your recirculating ball zone which actuated mechanism is common on General Motors vehicles he knew about that the screw nut Co imagine him getting that we’re out which actuated mechanism is common on Ford’s the ball ramp but most of the four is now how hats okay there is a ball ramp 2005 ford 500 down there and it’s got ball ramps on parking bank controls typically include all of the following components except what they don’t have a normal Lazar okay moving rapidly to replace the primary front cable of a parking brake system you should do all of the following except what let’s don’t remove the cable from the backing plate I’m always telling you guys not to do that because it’s too much trouble to put it back on there which of the following steps is done first when replacing rear cables why don’t we disconnect the cable from the equal you know what the equalizer is at that bar there’s a little bar the up and then have a spit instead going through it where you can adjust I mean it’s the bar that is actually yeah it’s kind of like the cable goes there to bar then that goes are just dead going back in other words each cable comes to the equalizer the equalizer connects to the cable that goes up to your partner and there’s a cell phone holdin up no know who this is hello hey come on over here that’ll do all right all right got an air conditioning job for moody all right that’s good innit okay which of the following steps is done what did I say that was a right number 17 which of the following steps has done last when replacing the rear cables remove the cable from the backing plate you only do that if you absolutely have to though which of the following cuz in this situation you would but if you don’t have to remove that cable from the back i played by the way you know how you get that out of there right you know the little cables got those little fingers that pop out when you’re how you get that out of there yeah who’s clam put on it and squeezes in finger dream just pull it out got it you know little fingers it pop out when you stick it through the back of plate but a hose clamp little bitty hose clamp tighten it up and then pull them out there that’s how you do it easiest way and everybody’s got a hose clamp around which of the following does not usually cause parking brakes to fail to hold corrosion is built up on the cable housing that don’t keep them from holding that makes them stay home parking brake linkage consists of all of the above and finally parking brake hand leaver assemblies are simple what ratchets with a pole alright everybody a little smarter now than you were when you came into this room your little smarter listen to that huh did you say dark oh yeah