More questions about vacuum...

[lemming303]

I was reading someone else's post and it brought up these questions in my head. How do those vacuum pumps work? And are they strong enough to work brakes on a vehicle with a very radical cam and no other vacuum accessories? What about the auto trans, doesn't it need vacuum to work as well? I am planning on running mechanical steering and brakes, but if I can use a vacuum pump to run power brakes that would be nice, but I'm also cool with mechanical brakes.

[moper]

IMO they work better than a can. Because even if you're idling, the pump makes vacuum. The can just stores the vacuum the engine made at some point while driving. If you really want power assist brakes (which are not needed for most cars with good braking systems) and dont want to worry about vacuum, I'd go with the hydroboost kits. They are a litle pricier, but well worth the investment.

[shadango]

Good question lemming.

I have non-power drum brakes on my car and so far they stop ok.

I get a pull to the left, so I guess either one of the drums is glazed and needs cut or one of the cylinders arent working as well as it should....even with that issue, the car stops......I was surprised at how easy it was.

I am considering going to front disks one day and wonder if it will be just as easy....

[twist]

Maybe what I went through might help. I switched the power drum brakes on my Charger over to power disc / drum with a SSBC kit. My engine just would not make enough vacuum for the disc brakes to work like they should. It does make enough vacuum to work the headlight doors and the HVAC flaps. I guess they take very little vacuum to operate. I purchased a electric vacuum pump kit from SSBC to help out. http://www.ssbrakes.com/commerce/detail/index.cfm?nPID=7655  The pump makes great vacuum pretty quick. The brakes have worked great ever since. I mounted the pump in my trunk on the supplied rubber mounts. The biggest drawback to this setup is the added noise the pump makes when it kicks on to build vacuum.  Fortunately it only runs when the car is first started and after using the brakes so its not something I can't live with.
The Challenger has manual drums all around so no problems there 

[moper]

One other clarification... there are vacuum pumps that pull vacuum for accessories, and vacuum pumps for the engine itself... They are nothing alike, so be sure you are searchign for the right type if you're searching...

[lemming303]

Well how much vacuum does an auto trans require to shift? I would assume it wouldn't take much, it's a very small actuator

[422STROKER]

Trans don't need vac, I think that's a gm thing.

Tom

[Chryco Psycho]

Both GM & Ford use vacuum on the tranny but no Mopar

[lemming303]

Oh ok. I haven't looked at mine so I didn't know.