Air Leak from brake panel area!!!

bjo09 · Post by **bjo09** » 15 May 2009, 05:36

Looking for help one more time, on S80 2.9 2002, went the vehicleis running we hear a air leak coming from withi the cab, around the brake panel ones we touch the brake panel the noise stop, has anyone had the same problem, ??? Is there panel adjument ??

Post by **mvsuzr** » 15 May 2009, 07:27

Can you be more specific?

Is the air conditioning or fan running? does it change if you manually change the fan speed?

There's a small fan in the center console, is this near where you are talking about?

drsugg · Post by **drsugg** » 15 May 2009, 08:27

I think he is experiencing a brake booster failure. I've had to replace a few with the symptoms I think he is trying to describe. If you replace pedal for panel, it fits

Post by **mvsuzr** » 16 May 2009, 20:20

Vacuum leak?

How easy is it to change? (shouldn't really have to ask, it is a Volvo after all...)

...and please don't tell me you have to take it to a dealer to reprogram it...

(Just kidding, I hope.)

ashotwell73 · Post by **ashotwell73** » 25 Aug 2009, 22:54

I just replaced the brake booster on my 2001 V70XC. It was making an air leaking sound that changed when the brakes were applied. The leak was under the bellows that surrounds the piston which applies pressure to the master brake cylinder. There is a seal around the piston between the piston and the body of the booster. There was a large piece of the seal missing.

The 2001 S80 is the same design. My daughter has an S80 and I checked it out today to see if they are the same as the V70.

It takes about 3hours the first time. You must remove the air filter box, the fuse box, the abs unit, the master cylinder, and the turbo intake tube to be able to remove the brake booster from the car. The worst part is working under the dash removing the four nuts which hold the booster to the fire wall. A 3/8 drive rt.angle head air ratchet with a deep socket and a swivel joint will make the work under the dash much less painful. I took the nuts off with a manual ratchet and I would rather have root canal work. The air tool with the swivel joint is the only way!!

You must disconnect the brake lines from the ABS unit and the master cylinder. Put rags under them to catch the drips. I used a syringe to remove all of the brake fluid from the reservoir before pulling the brake lines off. This results in much less fluid loss and mess. After all is replaced, I did a pressure bleed of the system to clear the air bubbles. You can get a pressure bleeder from IPD USA. I bought the bosster from IPDUSA also.

Good Luck! 97 850 T-5, many upgrades; 01 XC70 IPD Sways; 05 S60R stock; 87 740 GLE many IPD parts

Post by **dcarlson12** » 27 Aug 2009, 12:44

Guess there is no way to repair/replace the seal which fails/was missing?
Seems shame to have to buy a complete booster if it could be repaired....

schmeer · Post by **schmeer** » 11 Dec 2016, 20:44

I had the same problem as seen here in my Youtube video:

I could not find the simple ring seal that could be replaced from the interior (by disconnecting the brake pedal and slipping it off cylinder). I thought, if available the ring seal would cost just a few dollars and 20 minutes labor. WRONG. Two different Volvo independents quoted over $700 to replace the whole booster, TO STOP A TINY VACUUM LEAK!
So I notice the seal had a little ridge torn loose from when it had separated from the booster. So removed the frayed piece and pressed it in with motor running to let the vacuum help seat it. Then I remembered that I had some Dow Corning 732 Clear Multi-Purpose Silicone Rubber Sealant. I thoroughly cleaned and dried the seal near the firewall, ran the engine to create vacuum, then swabbed the ring seal with a generous dab of the silicone (careful not to get it on the piston). The viscosity of the sealant is rather thick so it sucked into any void, then I jiggled the piston to work it in. It drys to touch in an hour and fully in 24 hours. I put a little lube on the piston, then put the gray bellows cover back on (which I put a small cut in to get it place) and sealed that.

It has been a month and has not had any vacuum loss. No noises, no engine stalls and the vacuum switch goes off immediately after the engine is turned off. It cost me $0.00 because I had the sealant. But it costs about $7 for a 90ml tube.