Brakes Trouble Shooting

[jdv69z]

I've recently had my brakes requiring stiff pedal pressure from my foot. 69 Camaro with front discs. At first I suspected that my calipers were frozen, but I also have a hissing noise which seems to be at the carb throttle bores. I can hear it when the air cleaner is on, but it is noticeably louder when I remove the air cleaner. It been suggested that my brake booster might be bad? Hoe would one check the booster?

[ko-lek-tor]

Jimmy, By your own post title (trouble shooting), I would say you may be close to the culprit being under air cleaner. First: Check all hoses and fittings especially where you hear noise.  One way is to get a long piece (arm length) of hose, fuel line size works well, and put one end to your ear and use your other hand to move around area described till you can pinpoint where noise is coming from or visually inspect by taking off all related components (not booster though) and inspect condition, looking for a split or crack. To check your booster, I would use a vacuum pump, like the ones used to suck down an A/C system and see if the booster holds a vacuum.

[z28z11]

Jimmy,

I suspect the booster check valve may be involved. Try this link out for some easy checks:

http://www.hotrodders.com/forum/troubleshoot-brake-vacuum-check-valve-152616.html

All kinds of things to consider, but be methodical and you'll find it. Let us know -

Regards -

[Mike S]

 I had a '69 Grand Prix develop a bad booster check valve that caused a hard brake symptom and a very noticeable 'hisssss' sound coming from the firewall/booster area but mainly when I applied the brakes.

Mike

[jdv69z]

Thanks for the ideas. Will investigate further.