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.

 

Have serious hissing sound. How far can I let this problem go? Can't find specific 'brake boost assist' part online. Any links? Have tried forum sponsors. Part of the master cylinder or separate? Thanks very much and God bless!

 

I wouldn't let it go to long.
Not sure for a source I looked quick and didn't see anything.

 

First disconnect the battery, then open the hood?
Neat trick.

 

Battery is not under the hood.

 

What would the division of parts and labor likely look like at a dealership?
Thanks,
Guy

 

Im not exactly sure but I would say around $600.00 to $800.00 total.

 

When pulling out the booster, remember to keep the master sylinder as horizontal as possible. I tipped it over too much and got air in the brake fluid and had to bleed the system.

 

The brake line needs to be disconnected between

- master cylinder and ABS unit
- the 4 circuits that ABS unit feeds

To pull the ABS unit out (need to come out so the booster can come out) Air will be in the system and require a bleed.

 

You do not need to disconnect any brake lines at all while removing the booster.
I never disconnect anything.

 

How do I know if I need a new Brake Booster? I purchased my 2000 V70 over 2 years ago and never liked the weak brakes. I just had it inspected and got pads and rotors all around for $510. The mechanic said the calipers are ok.

Well, it seems now the brakes are weaker than before. Sure it stops... but sometimes I have to press REALLY hard. It's been 100 miles so I'm sure they are broken in.

HOW do I get these brakes to be more powerful? Also there is sometimes (not always) a clicking noise as I come to a stop (which did not go away with the new brakes). There is also a "click" noise in the console when I step on the brake pedal while parked. Is that normal?

 

Usually if the booster goes bad there is a hissing noise hear inside the car.

The clicking by the shifter is normal it is the shiftlock releasing.

 

thanks,
well... I hear no hissing... so that's good.
Maybe the brakes are not being bled properly... or there's a vacuum leak.
Can old brake fluid make a difference...

 

If it is not bled then it can cause an issue. Old fluid itself not really.
Maybe try bleeding it first.

 

Just had mine rebuilt by John Stuart rebuilder in Stoney Creek Ontario for $197. and had it re & re by local garage for $200.00 .Thought that was a good deal.

 

Hey tech, thanks for the great writeup, just fixed my hissing booster over the weekend...replacement ATE booster was $225 shipped from FCP Groton, much better than $1K to have the dealer do it.

A few additional comments for the next folks that find this thread:

I had to remove the upper engine mount to get the booster out...so the plastic engine cover had to come out because it was obstructing a bolt on the mount...and to get that out I had to loosen the turbo crossover pipe ('01 2.4T) because *it* was obstructing a bolt on the cover! Thanks, nameless Swedish engineer!

Don't forget to move your power seat back *before* disconnecting the battery...d'oh!

It's easy to not get the multi-pin ABS connector fully seated...if you don't, your IP will look like Christmas with all the lights...but fortunately they will clear themselves once you seat the connector properly.

You'll probably want a Rube Goldberg collection of U-joints and extenders to remove the 13mm nuts holding the booster to the firewall...especially if you forgot to slide your seat back...

Thanks again for the great how-to post...no more hissing and hard brake pedal!

 

Glad all went well.

 

Its not hard to replace the bake booster, just unbolt the master cylinder and carefully pull it free of the brake booster, then comes the hard part, you need to get your head under the dash so you can see were its connected to the brake peddle,

 

01 Volvo V70 with STC, is there is special booster for STC or do I order w/o traction control?

 

You need to order a STC booster.