I have a 1984 22R 2WD pickup. Something has gone bad with the power brake booster section and I wonder how I can tell if it's the booster itself or one of the gaskets on either side of the booster.

When I push the brake pedal in I hear a faint hiss the first few inches and then a louder hiss the last few inches of travel. When I hear the louder hiss the engine is also missing, trying to stall...classic bad brake booster symptom. Also the brakes take a lot of pressure to make them work, so the booster is clearly not working.

When I put my head under the dash to listen closely, the hissing is very obvious even though the booster is on the other side of the firewall in the engine compartment. This makes me wonder if the problem could be one of the gaskets that seal the booster on either side. Has anyone ever found this to be the case and how would I check for this problem?

Also, is it correct that any Toyota pickup brake booster from 1984 to 1988 will work on my 1984?

John