Chrysler Voyager - brake booster air leak noise in footwell

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Fri 18 Jun 2010 01:10
Chrysler Voyager - brake booster air leak noise in footwell - stbos

Hi, wondering if anyone has had this problem and know of a cure?

when i apply brakes they work great but i have a air hissing sound coming from the brake booster under dash on passenger side, wondering if this is just a seal that needs replacing or is the unit kaput?? any help would be nice , thanks in advance , 1997 3.3 petrol.

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Fri 18 Jun 2010 11:33
Chrysler Voyager - brake booster air leak noise in footwell - Peter D

I am not familair with the layout of your vehicle but what you are describing is a failed servo and unlike the 'old days' they can not be repaired. Regards Peter

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Fri 18 Jun 2010 12:22
Chrysler Voyager - brake booster air leak noise in footwell - bathtub tom

I'd say if it's a continuous sound all the time the brake pedal's pressed, then it seems something's wrong, but if it's just a brief pssst then that's normal operation. However it's probably worth getting it checked over properly particularly if it's never done it before.

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Sat 19 Jun 2010 10:23
Chrysler Voyager - brake booster air leak noise in footwell - stbos

Thanks for the feedback on my problem, If i gently stab the brake pedal the hiss stops, i was wondering if maybe it was just the seal???? wich is a just a case of replacing, but before i stripped it down( a proper pain to do access restricted badly) i thought i would see if anyone else had a similar encounter apart from minor hiccups all of wich are resolved the car is fab. ,, you hear to much of garages ripping you of for parts that are not needed just to boost profits.

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Sat 19 Jun 2010 10:47
Chrysler Voyager - brake booster air leak noise in footwell - bathtub tom

Are you saying you can this hissing all the time the engine's running? If so, then it needs looking at as, if it's petrol, you'll also be introducing air into the inlet manifold that could cause engine running problems.

If it's diesel then it still needs looking at.

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Sun 20 Jun 2010 05:11
Chrysler Voyager - brake booster air leak noise in footwell - stbos

Hi bathtub tom, i took the glove box out and behind it is the connection from brake booster (servo) to brake pedal the hiss is coming from the rubber boot covering the pushrod into the servo (the rubber boot has vents around the top) its here that the hiss comes from , if i slowly push the connection (brake pedal linkage onto the pushrod) about a 1/8 of a inch the hiss stops and does not come back until i brake , while im driving if the hiss comes back it will only stop hissing if i give a gentle stab at the brake pedal then it stops, other than this the cars brakes and performance is spot on, its not affecting performance nor the braking system (yet) ... ill get it looked at this coming week but im not to bad at repairs myself just need to know the prroblem part and i can repair it..

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Sun 20 Jun 2010 11:03
Chrysler Voyager - brake booster air leak noise in footwell - Peter D

Many brake servo's are not repairable these days, and even if you could open it up there are no sevice kits available, check with your dealer and local motor factors. Regards Peter

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Sun 20 Jun 2010 12:35
Chrysler Voyager - brake booster air leak noise in footwell - Peter D

Take a look at :

www.kfz-tech.de/Bilder/Kfz-Technik/HydraulischeBre...A" target="_blank">http://www.google.co.uk/imgres?imgurl=www.kfz-tech.de/Bilder/Kfz-Technik/HydraulischeBre...A

To help you understand. Note that with no brake pressure the vacuum it on both sides of the diaphragm and on pressing the pedal the valve opens and allows air in from the cabin and the vacuum then sucks the diaphragm towards the master cylinder thus assising the braking force. Regards Peter

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Sun 20 Jun 2010 13:26
Chrysler Voyager - brake booster air leak noise in footwell - stbos

Hi Peter D,

I want to thank you for shedding light on how it works now i have probable cause to replace the unit, after a closer inspection it seems the valve is still slightly left open and i cannot see any other solution other than replacing the unit.

your efforts for locating the information for me are truly appriciated and i hope that i maybe able to assist yourself one of these days . thanks again. your a star .. regards stu.,

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Tue 22 Jun 2010 02:08
Chrysler Voyager - brake booster air leak noise in footwell - stbos

Hi all, update, took car in to check out servo, would you believe it the rubber shroud around the piston im told should have its base on the other side of the plate at the base the rubber was wd40'd and twisted back behind the base and behold a silent brake, a red faced me but at the price of a drink im not complaining servo still was checked and deemed to be fine, and glad too as a replacement unit is not cheap, thanks again to all who gave feedback and your digging around for solutions for me , appreciated not end , again many thanks. stu

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Tue 22 Jun 2010 09:00
Chrysler Voyager - brake booster air leak noise in footwell - Peter D

I do not see how the reseating the dislodged bellows will stop the leak. It stop you from hearing it though. Here is the test. Run the engine for 1 minute , turn off and leave for 1 hour. Retrun to the car, do not start it and operate the foot brake, it should feel normal, then operate it several time and the pedal should become hard. You can usually leave a car overnight and this will be the case. If there is no assistance available, i.e. it goes hard straight away then the servo is leaking. Regards Peter

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