How To Test For A Faulty Brake Booster - Step By Step Guided Instructions

[@Nemesis74racer]

Of all the vids out there on youtube explaining possible/step-by-step how-to test for a faulty brake booster, this video is by far the best video I've seen. Job well done, sir! Job well done!

[@sentoneYYC]

Nice video helped me understand what happened to my booster. After leaving the car in the airport parking lot the parking pads and rotor were frozen shut. After forcing the release I notice an issue with a hissing noise in the cabin while pressing the brake. It operates normally when driving but when stopped it gets hard with multiple press on the pedal.

[@atlyoungboy]

Q

[@toddsmith5095]

Best instructional break video I've seen by far that actually knows what he is talking about. Well done good Sir.

[@GerardBurkeBurkesGarage]

Thank you

[@bigdaddydaddy3203]

I absolutely love this man’s accent

[@GerardBurkeBurkesGarage]

Thank you 🙏🙌

[@TheBillybushcook]

Good video though technically incorrect in one aspect, About the 7.40min mark - The vacuum is not only on one side of the diaphram but both sides under normal conditions. When the pedal is depressed, it blocks the vacuum from the rear side & then introduces atmospheric pressure to that rear side so the diferential pressure is what creates the "Boost"

[@johntrauger68]

Very clear explanation of your steps. Thanks!

[@watchandjewelryloft4713]

Great video. I just changed pads and rotors on a 2012 Fors Fiesta. Pedal seems to be fine woth one or two presses, but after that the pedal firms up and braking power severely diminishes. Booster behaves at it should with your tests. No hissing either.

[@t17bobby]

Did you ever post a follow up of how to trouble shoot oil coming into the brake booster? I'm having this exact issue. Thank you for the video, it was very detailed and super informative!

[@strawmancraig6897]

Excellent. My issue is a little bit strange. I have a Suzuki Ciaz. It requires the brake to be pressed to start. Just recently the brake is now hard whenever I start the car the next day. Performance is fine when the engine is running. Even after 30min when the engine is off, the pedal is easily depressed once. Overnight is hard again. I checked the one way valve and even replaced it. Still same. There's a leak somewhere!

[@strawmancraig6897]

Fixed ... replaced the booster .... leak was inside it.

[@KSmith-mw9tx]

Amazing vid I have a 98 honda Civic Break pedel gets very hard and stiff, while depressing the breaks with the engine running, front caliper locks up, both rotors and wheels feel hot to the touch, I depress pressure from calipers and I'm rolling again until I depress break pedel 2-3 more times.

[@zzfran]

Thanks. Great video. I have hard brake problem with my KIA Ceed 2020 diesel. Its hard occasionally after I start the engine, last a couple of minutes and then its normal again. The Service changed tandem pump but it got hard again. They didn't mention anything about the booster..

[@nicsmisznego4756]

How about It passed your tests but it keeps hissing? Is still bad?

[@Sequel7]

If it’s hissing then the diaphragm is ripped

[@sirenswhispering]

i bought a new jegs brake booster and master cylinder, i renew all the hoses, drums, and pads with lines, and there is no any leaking, my engine is 4.3 stock with holley sniper 1. I wonder why it happened sometimes, for example i drove about 45 min without any problem, when i wanted to park my car, suddenly i lose a brake and become stiff and immediately i push it again came back to normal. I did all of your test and could not find problems, as i said sometimes it will happen.

[@In.Spirit]

I just had a collision where the master cylinder was pressed on by the fuse box, no noticeable damage to the exterior of the master cylinder but the brake lines were pushed over a little (not pinched). My brake pedal is acting like the system is not getting enough vacuum, the pedal becomes stiff, BUT the brakes are EXTRA sensitive and do not fully disengage unless I come to a complete stop and force the pedal to the floor for a full range of motion of the pedal. If I'm in slow but moving traffic where I only partially brake, not coming to a complete stop, the brakes stick/drag and if I'm on the highway the truck starts shaking because it's like I'm riding the brakes and they're heating up so I have to pull onto the shoulder, stop completely and fully force the stiff pedal to the floor and release in order for the brakes to release. The idiots at the dealer said it's not a result of the collision, just a coincidentally failed vacuum pump. They're idiots, the brakes work, TOO good, the OPPOSITE of what happens with low vacuum. but the pedal is stiff, the breaks are SUPER touchy. What's the deal? Before I go play process of elimination, throwing random parts at the problem. 2017 Silverado, L86

[@user-yq2ue8do4m]

If the check valve is fine, then how can oil be introduced into the brake booster, seems highly unlikely. Even with a faulty check valve, airflow would not be reversed, since there is a vacuum. For this scenario to occur you would need a faulty valve or seal and a massive oil contamination from the vacuum pump or the intake manifold. The "oil" you saw was more likely brake fluid from the master cylinder, a bad seal.

[@akashnthampy3162]

Great video sir, I have one question, is it expected to get hard brake pedal at any time when the engine is running? When I am in bumper to bumper traffic, my brake pedal got hard multiple times and service center team is telling me that it is expected.. i narrowly escaped from accidents 3-4 times..

[@MiracleMAX]

Good methodical diagnosis - well done!

[@GerardBurkeBurkesGarage]

Thanks mate 🙏🙏👍👍

[@bigjay6743]

Thank you your video helped tremendously.

[@GerardBurkeBurkesGarage]

🙏🙏🙌🙌💪

[@dakkota27]

Same problem for me, VW Passat B6, 1.4 TSI CAXA, 2009. I already changed a brake booster, about 2 years ago and now I have the same issue, hissing noise and hard pedal. I was looking inside old brake booster and I noticed some oil but I didn't know how did get there. Now, thanks to tour video, I am sure the oil entering inside brake booster, was the problem. I was about to change again the brake booster but I have to see how can I fix the oil in the vacuum line. I have no idea Anyway, thanks again for your video Best regards from Romania

[@kennylavay8492]

is it oil getting in from the engine vacuum port or is it break fluid leaking by from the master cylinder getting into the booster. ?

[@LanceGoodthrust_]

That seems more likely than having engine oil pull up past the vacuum.

[@anthonydefr]

What would cause a hard brake pedal with too much assistance where you bearly touch the brake and it stops the car. The brakes seem to drag a little or something when car gets warmer but work fine when car is cold.

[@7minnow]

Nice! whats going on if the engines off pedals nice an hard ,, But start the engine gos right to the floor? i have no leaks Thanks

[@daviesad77]

New development loud hum from master cylinder area when shutting engine off.

[@castrolgtx5064]

Fantastic video thanks for sharing Ger👍👍

[@GerardBurkeBurkesGarage]

Cheers Eric 🙏🙏👍

[@ernstboston8554]

my 1994 jaguar xj6 4.0 . brake pedal very hard when applied. check fuel. relay, those are ok. air pump booster used trigger when step on brake., were is the module located in British style very good video.. very helpful .....

[@ricko3k]

Very clear and concise thankyou.

[@teveler]

Well said, I have a older Tacoma (1996). I wonder if you could put a old school gas filter on the intake side to reduce the oil leaks?

[@_J20_]

(Bmw e90) I test my brake booster all the test passed i guess, brake pedal sinks after engine start, no hissing but what may be the cause if when i press the brakes but the pedal very slow to return the engine is on, sometimes when the gear is on drive after i press the brakes it can stop or hold the car even i removed my foot from the brake pedal. I think its too much vacuum or i dunno???

[@cakeismtrader4227]

Usually just check value

[@Bristolchannelhunters]

Excellent video, very well done (for a change) and gave me all the info I needed to check mine, thank you

[@GerardBurkeBurkesGarage]

Thank you Keg.

[@ronineric9264]

You all prolly dont care but does any of you know of a way to get back into an instagram account..? I was dumb forgot my password. I love any tips you can offer me!

[@houstonbrysen7755]

@Ronin Eric instablaster =)

[@ronineric9264]

@Houston Brysen Thanks for your reply. I got to the site on google and Im trying it out now. Seems to take a while so I will reply here later with my results.

[@ronineric9264]

@Houston Brysen it worked and I finally got access to my account again. I am so happy:D Thank you so much you saved my ass!

[@faresnar09]

Really informative. Thanks

[@rudolphbennett3988]

Nice video and an excellent test examples.

[@atillaozturk7075]

Can a failing brake booster cause the master cylinder to reach very high temps so as to cause brake fluid to seep out of the reservoir cap??

[@masibulelenoquqa8790]

good morning boss i do have bmw x5 e53 have the same problem of hard brakes even now is not yet fixed any help for me

[@Dave_Stafford]

Great information.. thanks for uploading.

[@csababrezsan1980]

Hi there . Thanks for the great video . When you do the hissing test on the bmw is the engine on or off . When I do the test on my bmw there is no hissing with engine off but there is hissing when engine on . but I think that is normal . After changing my rear brake pads my brake pedal slowly goes down whenever I brake . Im not sure what happened . I forgot to loosen the cap on the expansion tank before pushing brake calliper pistons back . could it be that causing the problem ? thanks

[@peteraudley5628]

Simple but thorough . 👍

[@daviesad77]

Hello, great video....I have a Citreon Berlingo and have checked by using your examples all seems fine. Replaced abs module, servo and master cylinder and brakes still continue to get firm with use. Any ideas......as a bit lost etc.

[@kirstyhumphries4042]

I also have this problem would this cause all four brake callipers to stay on ?

[@anthonyonwuna2289]

Best explaination

[@GerardBurkeBurkesGarage]

🙏🙏🙌

[@LG_CAT_SUS]

Thanks so much! Super helpful!

[@GerardBurkeBurkesGarage]

Thanks for the kind words

[@dilligaf2386]

My breaks stick for 6 seconds before they release. I've changed the vacuum pump and pipe and non return valve is ok. Any ideas, do you think maybe the servo is not working properly. Great video

[@gabrielchifor8680]

Thanks good informative and clear video.

[@pelekass]

Thanks for Video my brakes hard on x3 i eill Check what wou had said!

[@IS3000vato]

super useful and informative thank you!

[@GerardBurkeBurkesGarage]

Thank you Samuel 🙏🙏

[@Dnasty1]

I do not have a hard brake pedal but when the car is running and in park if i pump the brakes I hear and air noise and it hever gets stiffer... I can just keep pumping. Also I have a choppy idle and when I braking to a complete stop sometimes the engine revs quickly. Are these symptoms of a bad booster as well?

[@bennyz6308]

Nice video informative ,

[@gordonl8319]

according to all videos and articles, there is a leak in the diaphragm. However, after following the 3 steps to test the booster, there is no vacuum leak externally. when applying the brake,the RPM jumps up and goes down to normal, the car goes forward 15 feet before it stops. this does not happen all the time,only one in while. Why? because it is a minor leak ? if the booster is replace, will this happen again ?

[@hookfish535]

Hi I checked my vacuum hose into the booster. When removed there was oil in the hose so obviously the pipe needs to be cleaned and the vac pump dealt too. Would oil getting into and along the vacuum hose be due to the smaller of the seals where it enters the engine be the problem. My larger seal on the outside cover is fine. Before I remove the pump I justed wanted to ask how we prevent the oil moving up the vacuum pump into the booster

[@noodleman551]

Well i came here because of my brakes that get hard when i stopped the car. What could be the rhing thats wrong???

[@juan-ksporty7348]

does anyone knows what will happen if i accidentally get to mix the brake hoses that conect to the brake master cylinder i would like to know what effect my brake system will have if i connected them wrong.

[@nickfloris103]

What if the pedal goes to floor after you start the engine

[@collinharris4913]

Hi mine becomes hard only if i dont accelerate the car

[@pardesi_life]

My car has that hiss sound when i press the pedal. but it has no other symptoms with fhe pedal performance. Can if just be a boot or foam problem

[@dorseyhayes5946]

Did you figure it out

[@pardesi_life]

@@dorseyhayes5946 one day it just stopped making that noise and it never came back

[@gremasaurusrex985]

Hi great vid. Can I ask. With you mentioning the oil in the system, are you talking about the typical engine oil? ... I have a small leak that I didn't bother sorting out in a rush and now I think I have a big problem (I've just noticed oil in expansion tank). Today my oil light is flashing while having correct amount of oil in and at the very same time I'm having trouble with my breaks (hard peddle)... I was thinking they can't surely be related? Its a VW T4 campervan.

[@krasinkrumov5990]

your oil pump and or vacuum pump was probably broken - did you fix it?

[@redmagic6676]

In my case there was definitely oil going from the vacuum pump through the hose and check valve into the brake booster. Now I have a vacuum leak in the brake booster. But I still don't get how the oil could come through the check valve? Is it necessary or advisable to change the one-way check valve too? Should it not only block air but also oil/liquids? It obviously did not block the motor oil in my case so I'm not sure if I should replace it together with the vacuum pump and the brake booster. I tested the check valve with a vacuum handpump and it holds vacuum. I also tried to blow air through by lung pressure and the check valve works fine it seems. Air goes only in one direction. I then poured in water through the hose and the check valve and the water does not pass the blocking side of the check valve. So it looks good. But then how did oil come through? I have a 2005 BMW 316i E46 with a N46 gasoline engine. The check valve for this type unfortunately is available only together with the plastic hose and it costs about €60,-. Thanks for the video Gerard!

[@LanceGoodthrust_]

Did you check the master cylinder? If that seal is leaking, cant it be pulled into the booster and then drawn through the vacuum tube? That would allow the fluid to pass an otherwise functioning check valve.

[@redbruce1999]

@@LanceGoodthrust_ I wonder too. I can’t see how the oil can pass the valve in the vacuum hose. Anyone?

[@Deni-td6bz]

perfekt

[@kickboxer8173]

nice

[@999momak]

my brake pedal is stiff as a rock when car is off. Is that bad brake booster? On the other car I can pump brake 2-3 times before it gets hard but on this one its hard always when car is off. While riding the car the brakes seem to catch at the middle when you press them. Seems like you can t precisly press them to stop slower or faster and they feel too soft. While on functional car I can already feel brake catching a bit at the top and they dont feel so soft Pls help me diagnose

[@krasinkrumov5990]

Did you find out what the problem was?

[@999momak]

@@krasinkrumov5990 didnt fix. But Its probably brake master cylinder making them soft while driving. And if you sudenly press brake pedal while driving and its really hard to press then its brake booster or brake booster hose

[@ChethanSG06]

Hi there.. I upgraded my brake booster to a bigger one (7"), Post that the brakes were very effective, however after driving for a while, the brakes start to drag and the pedal becomes harder. I have to disconnect MC from booster to release the brakes .. and again it works for 100kms without issues and then same problem repeats.. what could be the reason for this?

[@786benny786]

i replaced my brake booster.bought from scrap yard.after 2 weeks my brakes started to make grinding noise like calipers not releasing and then near enough car stopping the calipers release which you could hear.i left it too long not knowing the problem and then got to the point where the brake pedal got hard and could not stop if needed to use emergency stop.this also controls the fuel and air ratio in the engine.because i left it so long.the check engine light came on showing codes lean to engine bank 1 and bank 2 also p0171 and p0174 which also relates that their could be other issues such as maf sensor,vacum leak,lambda sensor,manifold gasket leak,injectors,clogged fuel filter,fuel pump fail and not enough fuel going to injectors,the car passed the emissions test but failed due to excessive smoke from exhaust.it smells of petrol and white smoke,alot of machanics couldnt find fault and made me spend alot of cash on parts that i didnt need.with bad brake servo you will also see rough idle while parked.engine missfire,because theres more air in engine and not enough or more fuel running through.so i would get the brake servo changed asap.hope that helps

[@anthonyoconnell9389]

Where are you based

[@brisbanelawncoring6102]

I have a diesel truck that when I do the pump then start up test it feels like it goes down very slowly after starting it up doesn’t go straight down but it doesn’t stay in same spot. Any ideas?

[@patkelly7999]

Good job Gerard, typical that it was not a split in the pipe:(:)

[@GerardBurkeBurkesGarage]

Cheers Pat, not the best result for the customer 😕 But we found the fault 😁

[@patkelly7999]

@@GerardBurkeBurkesGarage Fair Play 👍👌🙏

[@shaunpmarshall]

Advice needed ...when the cars running i car slowly press the pedal to the floor ..pump pressure i good ..master cylinder is good ...and no fluid leaks ....could this still be the servo ?