Vacuum pump

[Longesst]

Hey guys, 1993 7.3 n/a with original vacuum pump. Today the power brakes were only working intermitently. Pulled the hose off the booster and had vacuum. Didn't have a gauge on me but will get a reading tommorow. Before I just go buy a new pump I was just wondering if there was anything else that could be going on. I will replace the vacuum lines in the morningas they probably need it anyways, any other ideas are appreciated. Thanks

 

[jwalterus]

ummmm.... is the booster any good? probably the first thing I'd check if you have vacuum...

 

[Fozz]

Vacuum pump is probably on its way out. Is your emergency brake light coming on too? When that happened to me, later that week my pump failed while trying to slow down from a freeway off ramp! Luckly, I was close to home. FYI, the pulley needs to be pressed off and on. Napa carries the pumps.

 

[Longesst]

Does anyone know what the vacuum numbers should be? And thanKs for the tips

 

[87crewdually]

Minimum 21hg at sea level in 30 seconds of runtime hooked up at the pump directly. Then "T" in the vacuum gauge tester and readings should be within 3hg of 21hg. Obviously if your readings are significantly low on the second test there is more than likely a leak. If so start at the manifold on the firewall and unplug and block one circuit at a time until you regain your vacuum. Once vacuum is regained the last circuit blocked off will be the faulty vacuum circuit.

 

[Agnem]

You should get a brake warning light when you have low vacuum. Install a gauge and be done with it. Shouldn't be an IDI on the road with factory brakes without one. One that reads up to 25 should suffice.

 

[Longesst]

Thanks to all. Guage will be mounted immediately.