Hello everyone,
I have been searching the internet and don't seem to find a solution to my problem.
I have a 2001 V70 wagon with a leaking brake booster. The leak is coming between the yellow shiny rod for the brake pedal and the white plunger of the booster inside the car. Most of the info found online suggest to replace the black rubber gasket around the plunger.This gasket seems fine but the leak i have is coming from inside the white plunger!
Does this mean the booster diaphragm has failed allowing vacuum leak through the plunger and it's time for a new/used brake booster?
Thank you in advance for your time and replies !

Charles

I am so uncertain about this, please forgive if I got it wrong.

I believe the white piston goes in and out and gets scratched. There's a specific lube for the outside of the white piston. A guy posted pictures of his white piston which was scratched.

When I inspected mine there was an intact black rubber boot around the white piston and it felt like it was filled with a lube. I saw no need to destroy a good, non-leaking boot in order to inspect the white plastic piston.

As I recall deep scratches mean the end of the boosters service life.

I realize your problem is inside the white piston. Perhaps application of suitable teflon lube will reveal the fault by altering the leak's rate.

2001 is old enough. How many miles? Remember, lotsa people will be offline until the holiday is over.

Search here and on Matthews for "brake piston", or teflon "brake lube", or "booster piston"
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Our 3rd V70

Thank you for taking the time to reply! You got it all right!

The car has close to 200,000 miles and i believe it has the original brake booster. I did lube the white piston well using silicone grease with Teflon, there were no scratches at all. The black rubber boot around the piston is well intact and not deteriorated and no brake fluid leak from the master cylinder to the booster itself.
The vacuum leak is coming from inside the white plastic piston, using a rag stuffed inside the white piston will decrease the leak significantly.
I have read lot of threads online and watched You tube videos and the black rubber boot around the piston was the source of their leak, but the leak i have is coming from inside the white piston itself!
I guess i will start looking for another brake booster while waiting for more replies.

Thank you again for your reply and may God bless!

Charles

I had to replace my brake booster a few years. At the time I was able to source an exact ATE OE unit from Parts Geek. Price was reasonable then - not sure what you'll find now.

As best I remember, you'll have to remove the air cleaner box, master cylinder, ABS unit, and "swing" the fuse box out of the way in order to gain access to the booster. Since you have to bleed the brakes after reassembly any way, it's an opportune time to flush the system. Be careful in removing/replacing and adjusting the brake light switch. It's a rather cheap little plastic switch.

Not rocket science, but for me it was pretty much a full day's job.
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Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (STILL not road worthy!)

Hi Chris,
Thank you so much for the reply, much appreciated!