How to Test For a Bad Brake Booster / Brake Booster Testing

In this video show how I test for a bad brake booster and check valve. Testing a brake booster for leaks is pretty easy and doesn't require a bunch of tools. The exact vehicle in this video is a 2002 Toyota Tacoma pickup truck. Enjoy!
P0171 diagnosis on this truck: • P0171 Trouble Code: Sy...
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Tools used:
OTC 5213 pressure/vacuum gauge: amzn.to/2GZJgVM
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Disclaimer:
Due to factors beyond the control of the Big Dog50001 Automotive Channel, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. The Big Dog50001 Automotive Channel assumes no liability for property damage or injury incurred as a result of any of the information contained in this video.
The Big Dog50001 Automotive Channel recommends safe practices when working with power tools, in on or around automobiles or other vehicles, automotive lifts, lifting tools, jack stands, electrical equipment, automotive modules and systems, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of the Big Dog50001 Automotive Channel, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not the Big Dog50001 Automotive Channel.

[@BigDog50001]

Check out The Accord Project videos! Link to Part 1: kzbin.info/www/bejne/h2aphomAiah3pLs Link to Part 2: kzbin.info/www/bejne/gonKfJWha610eKM Link to Part 3: kzbin.info/www/bejne/pYWWgqp5aqx-npo Link to Part 4: kzbin.info/www/bejne/rJ65ZYGIq62MjpI Link to Part 5: kzbin.info/www/bejne/gIWyqKWQZsirqpY Link to Part 6: kzbin.info/www/bejne/rHW6qWppeaxmnbs Link to Part 7: kzbin.info/www/bejne/sHzcnGZmidB-pMk Link to Part 8: kzbin.info/www/bejne/rpDUZZRjec93kNE Link to Part 9: kzbin.info/www/bejne/rl63cmOLbdiMatE

[@bramblewoodhall4757]

Brilliant! Greetings from rainy England. I was stuck trying to fix my brakes on an Audi A6, which would work fine but occasionally suddenly fail. This was not improving marital harmony. I watched your video, where you explain how the servo assist system works and how to test for faults. Armed with this knowledge, I strode manfully to the carpark, where I had abandoned the dangerous car. Problem solved! - the vacuum feed pipe was not tight in the rubber tube that goes through the bulkhead to the brake servo. I wrapped ptfe tape round the serrated pipe end to make a tight seal and added a tie wrap round the rubber pipe to stop it coming off. The brakes work much better now. It was knowing how it worked that enabled me to diagnose and then to fix the fault: thanks for sharing the knowledge.

[@eddiemercado9310]

Thank you for sharing this information with us 🇺🇸

[@Bozemanjustin]

6:07 mine is firm with the car off, turn the car on drops almost all the way to the firewall

[@gvjester]

WOW!! Learned more about brakes in this 10 minute video than in the last ten years! You are the brake GOAT! MANY THANKS!!

[@ryszardjacekrusniak7993]

It explains EVERY aspect of testing the brake booster. Thank you,

[@BigDog50001]

Thanks 👍!

[@DanOnFire]

I think everybody else has already said it: you do a fantastic job explaining the how and why of each simple test. Thank you!

[@BigDog50001]

Thanks 👍!

[@225dog3]

I know this is an old video but I just want to say dude you just help me out a lot this video will help people for years to come

[@BigDog50001]

Glad it helped, thanks for the comment!

[@glasscitysocialclub]

It just helped me. Been driving myself crazy trying to figure out why my van only runs right when the booster vacuum hose is disconnected.

[@eddieesquivel1685]

I had recently replaced a fitting that fixed a vacuum issue (fitting on manifold) that had turned on check engine light. Parts store clerk said it was for brakes and whether I was having issues. We weren't, but the check engine light was on for vacuum issue. Light went away when fitting was replaced, but came back on several days later (I did not reset light, it just turned off when fitting replaced). Diagnostic showed no errors, but history showed brake issue. It's clear now. Video helped explain how vacuum loss could cause the "brake" check engine light issue. Thanks.

[@BigDog50001]

👍

[@GunnersRange]

I love the way you explained everything. You did this better than most other sites on KZbin. THANK YOU!

[@BigDog50001]

I appreciate the comment, thanks!

[@HomeMadeBoards]

10/10 mate. Straight to the point, great, simple, yet vital information other channels aren't addressing.

[@BigDog50001]

I appreciate the comment, thank you!

[@1LeMec]

Just helped me diagnose a the problem. Saved me from buying parts I didn’t need and some frustration. Many thanks!

[@BigDog50001]

Glad it helped, thanks for the comment!

[@jimmypage4162]

Couldn’t have done it better myself excellent video sir! Every possible easy way to check the booster/vacuum/master cylinder system. Thank you

[@lendanhoke9066]

Very well explained. Appreciate the accurate information! I Wish school teachers knew/explained their curriculum this well.

[@BigDog50001]

Thank you, I appreciate the comment!

[@capitanvonchickenpants8492]

They do! That's why our kids are becoming commies

[@darkskinwhite]

@@capitanvonchickenpants8492 I see what ya did there lol. agree. also doesnt help they encourage little boys to think they're girls.

[@TheKonakairay]

@@darkskinwhite look up yuri Bezmenov

[@grand73am]

Excellent advice. Helped me diagnose my booster. Thanks!!

[@GMoney-B]

I have bled my brakes 3 times for squishy pedal syndrome. The third time I bled my brakes I used a pressure bleeder and my brakes were great and fine for a couple months until today when the squishy pedal came back. I didn't think it was the master cylinder because it would get better and not come back after bleeding the brakes. Each time it would come back, it would seemingly happen over night. I did the last test that you described to do that tests your master cylinder, with the engine off. I pumped a bunch of times(6 or 7) to get rid of vacuum in the brake booster, then I held the brake for 15 seconds. My brake pedal held firm and didn't sink, it did do a really weird thing though after 15 seconds of having this very very slow pulsing that would push my foot back very very slightly almost not noticeable. It would push back for maybe 5 seconds in a gradient pulse, and then go back that same amount. Again, my engine was off, and the distance it pushed back was so so so small so I would think it wouldn't be an issue, but I also never expected it to have a gradually sweeping pulse pushing my foot back when the engine was off. I would think it is air in my system, or a leak? What do you think? If anyone else has any ideas or experience with this, I would really appreciate any expertise! Really wanting my brake gremlins to be stomped out after maybe 4-5 months of this now.

[@iRepairElectronics]

Great set of tests. My old truck must have a bad booster, when i press hard enough i hear it hissing and the engine RPM’s drops down. Lol 😂

[@brianpeacock9444]

I am an A.S.E. tech and this is an excellent video for b-booster fault trouble shooting.

[@BigDog50001]

I appreciate the comment, thanks!

[@sergedenovo2389]

BY FAR, the best video on the subject that I have found. Sincere thanks! Serge in Chicago. Imma go see!

[@isjesse1]

Thank you so much for being so clear

[@John-wx3zn]

I am impressed by your football acheivements. Congratulations. You were a part of an amazing team and you are an amazing man to help people with your education. Thank you for this awesomely articulated video. Your shared education on this matter is a big help to me. I hope more people that make videos share their sports acheivements at the beginning like you did. Go Laney!

[@4bangerftw]

I have to pass a knowledge exam soon to change class as a mechanic and your video are very helpful, you are a great teacher.

[@BigDog50001]

I appreciate the comment, thanks!

[@madinanababi8094]

Hi

[@jimlawson1953]

I'm wondering if you have any deaf people in your family. The way you communicate through you hands is phenomenal. Thank you.

[@ronniephillips4598]

Wow, to the point and very professional, I was able to check some things while actually watching this video…great content I will be following you from now on!!!

[@BigDog50001]

Thanks and welcome!

[@markboymer9988]

Great video on simple brake booster vs master cylinder testing for brake issues

[@belowfray5251]

Thanks so much. Great reminder of how to check valve

[@dr.drewskii8823]

This video was very helpful!! Thanks big dog!!

[@mckoylach1622]

Great demonstrations of the diagnostic procedures,thanks for the video....

[@BigDog50001]

Thanks for the comment!

[@matthewhomer9369]

Great guy very good teacher helped a lot Thank-you.

[@feliperigau7353]

Very informative! My fluid level was down below minimum but after topping it off the light remained on. The dealership recommended tapping the reservoir to free the measuring arm in the reservoir. IT WORKED!! LIGHT OFF!!

[@BigDog50001]

👍

[@gunsofsteele]

Thanks for the video! Releasing the clips meant my wife had to assist to pull the switch out while I pushed the keeper clips in. Nothing like fumblefarting my way through it. 😂 2009 Chevy Avalanche. Key positions; all the way counterclockwise = Lock, 1st = Acc, 2nd = Run, 3rd (spring loaded) = Start. This truck does not turn counterclockwise for Accessory. Thanks again!

[@dimitrig3739]

Good, thorough explanations

[@MrLESRAJ]

Excellent video, on all tests, thank you.

[@deepramgariadhiman9875]

Good job Sir it's a perfect example to Check Boosters .I do it as you do

[@BigDog50001]

👍

[@angelmoreno8000]

Great video sir. Keep up the great work!!!

[@Ingyar]

Nice explanation. Thanks! 👍

[@dustinwilce1766]

Great video bro keep it up this helped me diagnose and fix my brakes

[@lancecluster]

Nice video, Seems to apply to my older volvo xc90, thank you for making this

[@EllisIsaacks]

GREAT video I never knew how to check.

[@BlackDomeJerome]

Very informative and easy to understand. Thank you

[@BigDog50001]

I appreciate the comment, thanks!

[@markstevens7709]

This helped me out so much, best video regarding the topic

[@BigDog50001]

Thank you, I appreciate the comment!

[@robertt3551]

This helped me out and saved me from a $300 repair job. Thank you!

[@BigDog50001]

Glad it helped, thanks for the comment!

[@TruckerReviewed]

This was very informative

[@robadventure8007]

Very well explained, very helpful. Thats exactly the problem of my break!👍👍

[@BigDog50001]

👍

[@mrkttrdr2919]

thanx, nice thurough explanation for all tests

[@georgemitchell7420]

Great help and simple to understand! thank you.

[@BigDog50001]

Glad it was helpful, thanks for watching!

[@denk25143]

yes this help it was master cylinder and now i learned how to appreciate a power booster

[@charliediver1560]

Another very helpful video thanks for posting .

[@BigDog50001]

Thanks 👍!

[@steveplowman4005]

Great info! Off to diagnose my problem. Cheers Steve

[@kabunyankim7751]

Thank you very much! Very informative video that answered my questions . God bless!

[@natanaelcalderon3937]

Thank you, following your instructions I determined the issue was the master cylinder. Replaced the master cylinder on my 2010 acura rdx and it no longer sinks.

[@krisztianadrian8528]

Thanks a lot ... Very good explanation..👍 I will do some checking

[@charlesdryg8452]

Excellent diagnostic demo.

[@BigDog50001]

Thanks 👍!

[@charlesdryg8452]

I attacked the problem as demonstrate and I won big-time. The first thing was to test the one-way valve. Bingo. On my valve there is a side tap to allow for an easy system vacuum check. It has a rubber slide on cap to seal it when not in use. On mine, the rubber cap had totally rotted to failure. Easy $4 fix. Thanks a bunch.

[@marcusdarnell3348]

Thanks big dog this helped me out a lot!

[@BigDog50001]

Glad it helped, thanks for the comment!

[@blujan52]

Nice video, clear and easy to follow.

[@BigDog50001]

Thanks 👍!

[@nune44]

Thanks for the knowledge man.

[@BigDog50001]

I appreciate the comment, thank you!

[@kengardner5097]

Excellent vid Big Dog50001 Professionally done.

[@BigDog50001]

Thanks for the comment 👍!

[@cedarbreezewoodwork]

very nicely done! thank you

[@JuanDiaz-pq4wb]

Thanks to your great video I was able to realize that the defect of my toyota tacoma is that the vacuum brake booster does not work well and I replaced it and fixed it. Thanks you very much for sharing your knowledge and experience. Thanks sss👍👍👍👍👍

[@BigDog50001]

👍

[@rjmlondon]

Excellent and informative

[@capncharlie7894]

great video thanks for sharing your expertise

[@shanemike3070]

That was very helpful, thanks

[@boatkid888]

Outstanding information! Thank you!

[@BigDog50001]

Thank you, I appreciate the comment!

[@itzikvil1]

amazing movie so informative and so concise thanks again I am going to apply to my car :)

[@jossefjossikajit4169]

FANTASTIC TEACHING ❤

[@bobbylong2202]

Thanks this gives me somewhere to look

[@haxificality]

very informative. thanks for sharing!

[@BigDog50001]

Thank you for the comment!

[@cksanford9897]

GREAT video sir and thank you.

[@BigDog50001]

Thank you for the comment!

[@andyclemente4205]

Thanks for the video. Very informative

[@BigDog50001]

I appreciate the comment, thank you!

[@richardprice7107]

Thank you! Not sure what I liked more...the tutorial or the detailed explanation! I'm on my way to properly diagnosed my brake booster!

[@BigDog50001]

👍

[@nonnoziccardy4353]

Great explanation and video!

[@BigDog50001]

Thanks for the comment 👍!

[@allahonfingerprint3800]

Thank you Very informative

[@patrickwinchester5573]

Thanks for showing a brother from a different mother

[@BigDog50001]

No problem 👍!

[@victorgarrett8795]

Right on man thank you so much!

[@donchan1622]

Awesome video great details and straight to the point…..! Love it man thank your…!

[@BigDog50001]

Thank you, I appreciate the comment!

[@marcior.2153]

Thanks Big Dog50001. ;)

[@dapoutdoors]

🤜🤛 great teaching bro

[@stephenwalford774]

Great info..thanks

[@ashfaqattar8801]

Very well explained... nice information.... thank you...

[@BigDog50001]

You bet , thanks for watching 👍!

[@jeffbeguinmusic7157]

Fantastic video - thank you!

[@BigDog50001]

Thanks!

[@charlesmicallef4673]

Really good video!!!

[@Nookends]

Awesome video thank you!!!

[@BigDog50001]

👍

[@samuelhelderman]

Thanks so much. I liked it so much I subscribed!

[@BigDog50001]

Thanks and welcome!

[@Nyck461]

Great video. A lot of details.

[@BigDog50001]

Thanks 👍!

[@paulc2548]

Thanks for sharing the video! I have a 2008 Highlander and has spongy brake and the brake pedal sank almost to the floor. I will do some tests :).

[@JoseMedina-jn3nj]

Congrats! Excelent video I understand petty much everything you said sr I like the way you explain very profesional with no loud music back ground.. thanks..

[@BigDog50001]

Thanks 👍!

[@arthurfricchione8119]

Dave, excellent video. I noticed that Big Dog 50001 coffee mug in the beginning. If you have any extras I would love to support your channel. Your videos are excellent. Thanks for your time and effort.👍👍👍

[@BigDog50001]

Thanks Arthur, I appreciate the support! I will let you know if I get extras.

[@TheDisgruntledMechanic]

You do love your coffee mugs Arthur! haha!

[@arthurfricchione8119]

Mike what ever gets us thru our day. You know what I mean. Take care bud 👍

[@TheDisgruntledMechanic]

@@arthurfricchione8119 yes sir! And I appreciate it!

[@mikedavis1069]

To "THE" point... Great vid thank you Sir...

[@MixinGasGarage]

Thanks for the help

[@BPerez-ou6ux]

very very helpful. Thanks!

[@BigDog50001]

Glad it helped, thanks for the comment!

[@mcdavidhome100]

I really appreciate the clear and concise explanation you gave. I had no idea as to how the Master Cylinder and booster system worked until now. Thanks

[@BigDog50001]

👍

[@danreynolds8028]

Fraekin' Great job, Man. Now I know how these puppies work. Liked and subscribed!

[@BigDog50001]

I appreciate the comment, thank you!

[@danreynolds8028]

@@BigDog50001 I meant "Freakin".... When your spelling starts to go bad, you know you're getting old... Keep up the great work!

[@AreaCode862]

Well done 🤝💪

[@barneygordon2585]

GREAT VIDEO THank you

[@elcoyotecojodeldesierto2300]

Very helpful video.

[@BigDog50001]

Thanks!

[@martinguitarhd28]

Thanks Dave for the excellent information and detail that you went through. Very clear and to the point.

[@BigDog50001]

Thanks for the comment!

[@tech.automobilemaster.1017]

Good idea guys.

[@DaMacy1989]

vacuum hose sensor was broken at the stem! Thank you!

[@bmlarkins1]

Great video.

[@richramos2689]

Good information. Thank You.

[@BigDog50001]

I appreciate the comment, thanks!

[@surgeneral108]

Excellent video, perfectly explained

[@BigDog50001]

I appreciate the comment, thank you!

[@dagorilla5177]

Great job 👏🏾

[@BigDog50001]

Thanks for the comment!

[@jimlawson1953]

Don't get me wrong, but the way you move your hands is great!