I need to replace my brake booster on my 1990 740, I found a 240 at a u-pull it. is it interchangeable they look the same??????

just a follow up....the booster is the same EXCEPT........
the damn bolt patten is way different. I picked up a booster from u-pull it for 25 bucks... not fun pulling it, just cramped and had to get to the bolts...
an offset 13mm did the trick.
so now my options are either drill new holes through the firewall, or take the booster to a machine shop and have them weld new bolts in the right place..
Ill let ya know what I did and how it worked...
BTW... The Brake booster was bad. when I pulled it out of the 700, it was rattling like broken stuff floating around inside of it.....

I'm pretty sure it'll work, and they can't be that expensive used.

I've *never* heard of a failure, and we sold tons of these cars at the dealership I worked at.

What's wrong with yours to make you suspect the booster?
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Rob Bareiss, New London CT ::: '87 244DL/M47- 234K, '82 245T/M46-182K, '84 242DL/AW70-100K, '89 244DL/AW70- 212K and I miss my: 86 244DL 215K, 87 244DL 239K, 88 744GLE 233K, 88 244GL 147K, 91 244 183K

The brake pedal is hard and it brakes slow and makes a humming type noise when brake applied, also I pumped the brakes about 15 times then started the car and cant tell any give once started. I replaced the check valve, it also does somthing really weird, when i apply the brakes the idle goes up to about 3000 rpm.... so im thinking its a vac leak there.
thoughts and suggestions ......many thanks

I think the one on our 91 is bad. You can hear it leaking vacuum after the engine is shut off. The pedal on that car is much stiffer than on any other Volvo I own as well. The leak seems to be coming from the gasket where the 2 halves are crimped together. I could change the sound of the vacuum leak by rapping on it. I haven't done anything about it for over a year so it's not a critical repair, but I really do think it's bad.

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Volvo Farmer:

20 Volvos '58-'91