S60 Brakes: Hissing noise from brake pedal

[boggymarsh]

It cost me about £450 at the main dealer to have mine done some two years ago and that was with a loyalty discount card! Mind you, atleast they did a good job and didn't muck the car up like a local garage did doing a simple alignment check... slightly different issue I know!

[YellowPinkie]

Thaks for that. It's getting worse on mine now, I'm off to Vegas in three weeks, so I'll try and win enough to get it fixed...

[fhz2717]

I replaced mine last year.Got one from a breaker for about £80 and my mechanic put it in for another £60 of so.So not the end of the world.

[YellowPinkie]

Originally Posted by fhz2717

I replaced mine last year.Got one from a breaker for about £80 and my mechanic put it in for another £60 of so.So not the end of the world.

I've got all the kit, engine crane, and space to do it so that re-assures me. Was just concerned I'd buy a second hand one and it'd be no better!

[westbranch]

Chris H . can you tell me what the search parameters you used were. I have looked at Matthews site but no luck so far.

thanks

EJ

[Jim314]

Originally Posted by YellowPinkie

I've got all the kit, engine crane, and space to do it so that re-assures me. Was just concerned I'd buy a second hand one and it'd be no better!

Wow, having to pull the engine to replace the brake vacuum booster!

Isn't there any sealant that could repair these leaks? Are the leaks in any specific place? Couldn't one just smear on some epoxy sealant, like 5-min epoxy? Since the interior is under vacuum, sealant should be pulled into the hole. Of course if it is rusted through over an extended area that would be different.

[YellowPinkie]

Originally Posted by Jim314

Wow, having to pull the engine to replace the brake vacuum booster!

Isn't there any sealant that could repair these leaks? Are the leaks in any specific place? Couldn't one just smear on some epoxy sealant, like 5-min epoxy? Since the interior is under vacuum, sealant should be pulled into the hole. Of course if it is rusted through over an extended area that would be different.

That's kinda what I was hoping, but the leak is in the diaphragm or valve and not external. Absolute nightmare. Still not done mine yet, but the idle is getting terrible (unmetered air) and we have an annual inspection in the UK which also has an emissions test, so I'd imagine it'll fail that when it comes due in a couple of months...

[Jim314]

From diagrams of vacuum boosters I see why spraying WD40 around the rod going through the firewall might in some cases temporarily reduce the hissing sound of a leak. It either temporarily plugs a leak in one of the valves which admit outside air to the 'push side' of the diaphram or it causes a seal to temporarily swell and might give a somewhat longer lasting improvement, but the improvement would not be long enough lasting to be a repair. I guess if something was preventing a valve from closing fully and the WD40 washed it out, then that might be a long lasting repair, but that is an unlikely cause of a leak.

Changing a vacuum booster on a LHD is evidently much easier than on a RHD. (See http://www.youtube.com/watch?v=leW0w...eature=related. A rotten shame that the engine has to be lowered out of the way in the RHD Volvo!

[s60.i@n]

I`ve just had a split diaphragm on the servo on my Alfa GTV, symptoms were hissing only when the pedal was depressed.
If you think the job on a Volvo is hard, to reach the brake cylinder required the inlet plenum to be removed, to do that required removing the front part of the exhaust . Not too bad, but the servo is on the other side of the firewall! to get that out you need to remove the dash, the steering column, and the whole pedal box :-o

The procedure in the repair manual for LHD is about 2 paragraphs, compared to probably 20 or so pages for RHD!