So after doing some research, I have come to the conclusion that the air rushing/hissing noise coming from my breaks is the booster.

How much have you paid to get this fixed?

Is it possible to do it yourself with little mechanical knowledge?

How long can I go without fixing it?

Thanks.

 

Have you lost power brakes?

Do you have idling issues?

A major vac leak on a brake booster would be very noticeable on many different levels, including likely codes...

If you are sure of this, check the brake booster vac connection and the grommet...

 

 

I just find it extraordinary that people who ask for help don't bother to reply to simple questions in order to assist them.

I need some help please.

If I press down the brake pedal I get a mid range hiss / puff. Sounds like it is coming from the brake pedal itself. If I pump the pedal with the engine switched off, the hiss stops after a couple of pushes. If I start the engine, the puffing hiss returned when I depress the brake pedal, then and only then.

I have not noticed any problems thus far with braking, and I drive in a mountainous region.

I have not seen any error codes thus far.

NB. I just noticed that I have posted this on the S80 forum... my car is an 850 T-5R.. I will post it there. Sorry

 

Well, I have replaced the booster once AND I WILL NEVER DO IT AGAIN. I unfortunately have a 1999 S80 with DSTC. Don't buy one of these as any part stamped DSTC will cost you an arm and a leg FYI.

The part itself for non DSTC vehicles is fairly inexpensive but replacing it can best be described as being waterboarded. There is a step by step somewhere on this forum or on the web but it all boils down to the last step to remove the thing. There are four small locknuts underneath the dash that hold the booster onto the firewall. They are fine threaded LOCKNUTS and the shafts have to be 3 inches long. There is NO way to get a socket on these things without pulling out the dash and even if you do, you probably can't use a socket until the nuts are much further up the shafts due to their lengths. You will have to get your head underneath the steering wheel with a small open end wrench and 1/4 turn at a time, unwind these things. It took over 2 hours for me (6' 200lbs) to do this and I removed the driver's seat for better access. I had to come up foir air at least 15 times as you will need strong wrists to turn these things and your arms will get VERY tired. It is a brutal procedure to say the least and when I put the new one it, I only put 3 of the nuts back on because I simply had had enough. I was sore for 3 days because you have to be a contortionist to do this with any kind of comfort.

When I reinstalled it, I wound the locknuts up and down the shafts of the new booster BEFORE I reinstalled the new one to make them turn a bit easier.

I guess pulling the dash would make it easier but I knew I would be breaking brittle old dash clips and possibly cracking the dash doing it.

The inside the engine part is pretty straight forward but getting the booster out and the new one back onto the firewall takes some puzzle solving skills and a little tugging and pushing of items that will make you wince a bit.

It truly is a job for the brave and avid Volvo lover.

The answer is YES, you can do it yourself and save a bundle but it will test your resolve. You will need one fairly unique tool to get the ABS module off but I found it cheap at Harbor Freight. I think it was a T5 torx SOCKET (not the typical drive but a socket). Might be wrong on the size.

Cost for me for a DSTC branded booster and installation at a shop was quoted north of $1000. A new DSTC booster online runs over $500 and NEVER buy a used one. If you have a NORMAL Volvo, the booster online is only $125 or so.

 

thanks for killing my morale, ill replace mine on the 2000 s80 t6 and let you know of any PTSD.