Brake Booster replacement:

First start by Disconnecting the Battery.

Then open the hood and remove the Upper torque mount cross member.

Next remove the Air filter housing.

The remove the Big Cover over the Relay/fuse panel under the hood.
Once the cover is off remove the 13mm nut for the Positive cable.

Then remove the 2 screws securing the Relay box into place.(one of the screws is under where the positive cable just came off)
Unplug the one harness from the box and move the box to the side.

Then reach under and unplug the ABS module. There is 2 plugs. One you have to push a little tab and fold the cover back to release the plug. The other is 2 push tabs then pull.

Ok here is where it will get a little tricky. Look where the ABS pump motor assembly bolts to the body. There is 3 10mm bolts remove them and make sure the pump motor is loose.(No need to disconnect the lines)
Remove the 2 screws holding the Master Cylinder to the booster.
Unplug the sensor in the booster. Remove the Line and Valve from inside the booster.

That should be about it from outside till the booster is loose.

Inside the car:

Remove the Lower dash panel on the drivers side.
Then remove the clip holding the brake pedal to the booster. Either slide the Pin out or slide the Arm off.(Forget which it has). Then remove the 4 13mm screws holding the Booster to the Firewall.

Now go back outside:

Then slide the Master cylinder off of the Booster and kind of pull and move to the side.
Might require Carefully bending some of the lines. Then slide the Booster out.(Most of the times it takes some work to get it slid out. It might take some time to slide it out just take your time.

Then install in reverse order.

It will take a little time to do. About 1/2 a day at home with Hand tools.

 

would you reccommend purchasing a new brake booster , or can I get one from the junkyard from a wrecked s80. Also wondering could I get one from another model volvo, are they interchangeable? Thank you

 

I would buy new because if you buy used it might be the same way.
Im not 100% sure but the S60 and V70 might be the same.

 

depends if it has stc, dstc, or just abs

 

aaa

 

Most places will charge book time no matter how long it takes to replace it.

 

aa

 

aa

 

i have a two week 2001 S80 2.9 with stc and my brakes hiss so i have come to the conclusion that it is brake booster since it seems to be a common problem so here is my question where i can find a new one for cheap volvo and fisher tires told me that its 700 for the booster and fishers said 620 so where did you find yours and hopefully for cheap. The labor was 260 is that okay for that type of service? THanks for the help in advance.

 

We just bought a 1999 Volvo S80 T-6. We noticed on the test drive that when the brake pedal was released after a stop there was a slight hiss or whine from the brake pedal/booster or something else under the dash. It only happens on release of the pedal. There is no loss of brake power what so ever...Idea's, is this a brake boost issue? The car came with the DSTC option.

 

Sounds like yes the booster is leaking.

 

sounds like mine is leaking as well... I just assumed that was how the system was designed..
for the first 1/3 of the pedal I dont really get much brake response but after that it seems to work fine...

how much should a new brake booster cost?

thanks

 

They are pretty expensive.

 

With DSTC it is around 500-600. W/o DSTC is around 200-300
I just special ordered one from california with DSTC for 220 through a car parts company I use often, so it is possible to get it without destroying your wallet

 

incase i dont get any responses on my recent thread this seems to be the right place to ask this...
anyways is the booster supposed to hold vacuum when the car is off???

or why is my vacuum pump working when the cars off???

 

Is the electronic valve broke inline between the pump and booster?

 

how do i find out?? its not broken like visually or anything... if thats what your asking. electronically maybe??? any tests i can run or would i get fault code?

 

Welp here's my story. 2003 S80 T6

Day 1. Car is perfect. Super happy, nothing wrong.

Day ~200: Really quiet hiss on release of brake pedal. Also note: electric sound after I turn the car off. Coming from just behind the engine on the driver's side. No change in braking ability.

Day ~220: Take the car in. Idiot can't find anything wrong, even though I show him the sound. $300 down the drain. Still brakes fine.

Day ~230: Damn loud hiss every second I'm in the car. Brakes fine, still.

Day ~260: Noticable change in braking ability. It's about half-way between Normal and "I forgot to turn the engine on, car is reversing backwards, and brakes are freaking hard to push."

Next week: Shop. Already confirmed brake booster with the people at the shop. Will drop around $650 total.

 

I'm having the same issue, when I release my brake I hear the hissing sound. I looked up brake booster on Amazon and came across this link: Amazon.com: A1 Cardone 533102 Remanufactured Power Brake Booster: Automotive

Can anyone vouch for this, or just tell me if I have the right part? Thanks.

 

You have to make sure it matches what your car has. STC DSTC etc.