Intersting comparison PM s. VAC brake

[turbo nasty]

Thought about the swap from parts relied upon between the 2 and it seems the vac definetly has fewer parts to go out. Just a different perspective/angle on the subject.

VAC
1. Check valve
2. MC internals (seals,etc)
3. Vac hose

PM
1. Accum
2. Switch
3. Pump motor
4. MC internals (seals,etc)
5. Hose
6. Wiring and fuse

 

[turbofish38]

You left off the vacuum booster itself. Two parts on it that I know of. The diaphram and the air control valve. You could always go to the extreme and add the vacuum source as part of the system. If you have a motor failure than you loose your vacuum which makes the booster useless. Well not exactly useless. At least you can overcome the hydraulics a lot easier than the PM.


I'm currently working on a junkyard electrical vacuum pump swap for the vacuum booster. It uses the existing electical wiring of the PM for power. And a MAP sensor to kick it on and off. If I ever get a minute to finish the project I should have some test results to report on. It works pretty good sitting on the workbench anyway.

 

[turbo nasty]

You beat me too it just realized I left that out and was gonna post it up.

VAC
4. Vac Booster

Sounds interesting on the vac pump setup. Lets us know when you get it wrapped up.

 

[jdpolzin]

Ever think about adding an electric vacuum pump to eleviate loss of vacuum from the motor? I believe the 80's deisel wagons had an electric vac pump.

 

[turbo nasty]

Ever think about adding an electric vacuum pump to eleviate loss of vacuum from the motor? I believe the 80's deisel wagons had an electric vac pump.

Yeah read Turbfish38's post

 

[turbofish38]

The vacuum pump I'm using is from a 86 Caddy Seville. It's also used on the 85-90 Deville. The MAP sensor is from a 97 Deville with the Northstar. In OEM form it actually is mounted on the booster and provides a vacuum signal to the PCM. I lucked into that by mistake. I plan on running a hose to it. If you know how to rebuild the booster than you could always drill the hole and mount it like the factory did on the Caddys.

Those old diesels used a gear driven mechanical pump. Both the Olds 350 and the Chevy 6.2. Some of the gas 307 big cars used a belt driven pump. Some of the 2.5 TBI IronDukes used one that look like a fuel pump and bolt to the block. The electric GM pump is getting hard to come by. There was another version used on some mid 80's FWD cars with the 2.8. The Caddy one I'm using is still plentiful in the boneyards. I recall the old Isuzu diesel in the Chevette and LUV truck had the pump mounted on the back of the alternator.