help 240 brake booster problem!
 

Hi, I have a new to me '85 240 sedan--I had noticed that the button on top of the shift was sticking in reverse and this morning it stalled on me as I was reversing. Started up with no problem but shifting seemed weird when I was speeding up and slowing down (excuse bad terminology, I don't know much about cars but want to learn!)

I took it into the mechanic (Volvo specialist) who said that there was a vac leak in the brake booster

here are my questions:

1) can I drive safely on this, at least back to the mechanic--I drove it home with no problems (the mechanic had said he raised the idle a bit to compensate)

2) the mechanic couldn't tell me if the new part was supposed to be 8 inch or 10 inch, is this reasonable and would another mechanic be able to figure it out

3) I would like to buy the replacement part as opposed to have the mechanic order it for me, hopefully I can find a cheaper one on the internet--any advice in going about doing this

4) any other stories, etc? about this? is there a chance this could be a misdiagnosis? again, the brakes have felt totally fine..

any help much appreciated!!

ps
 

the other thing is that I haven't ever heard the hissing noise associated with this problem--could it be a different (and hopefully less expensive) issue?

Regarding the hissing sound that you hear - does it originate from inside the car or do you hear it under the hood? If it is coming from the center console inside the car, then you probably have a faulty vacum check valve. If this is the case, you will hear the hissing sound when you turn off the engine. You also may hear it on hard acceleration.

If this is the problem, the fix is relatively simple and you can do it yourself. On top of the intake manifold, there is a black & white plastic valve that has a larger hose going from the intake manifold and a smaller hose coming out that runs through the firewall into the passenger compartment. Remove the hoses and try blowing through both ends. If you can blow through both ends, then the valve is faulty. You can find replacements online fairly cheap.

The SHIFTER sticking is unrelated to the possible BOOSTER leak... You say you don't hear a leak? So, what, the mechanic diagnosed a vacuum leak so turned up the idle, and wants you to get a new brake booster? Need more info...

the thing is that I don't hear a hissing sound at all, which is what makes me think that it might not be the brake booster--the brakes also don't feel hard for me, the only thing that has gone wrong is the engine stalling on reverse and feeling like the (automatic) gears were shifting rougher than usual. I am going to take it to a second mechanic and see what he says, but the first dealership did scare me enough about the brakes that I feel hesitant even driving it over there---his words were that they could go out all of a sudden, "like a heart attack"...

The brakes don't go out like that, even if you lose all the vacuum, you'll have brakes but you'll need more pedal pressure. I'd drive it without worry...

I ended up taking this car to another mechanic and he said it wasn't the brake booster at all, it is the rear brakes, which is just as pricey but makes more sense to me given that it didn't feel like a brake booster! thanks for the help!