Someone once told me newer Cavalier's had electric vacuum pumps. Due to cam profile, I need to go this route. New one from M.P. is $349 U.S. I'd rather scourer the bone yard. Which make and year should I look for? T.I.A
I had the same need for an electric vacuum pump when I recently installed a 9" power booster to upgrade my manual disc brake system. I spent the $$ and got the GM electric vacuum pump because I only have about 8" of engine vacuum at idle and didn't want reliability problems using an older used unit. I got the pump from Classic Performance Products in Buena Park, CA. They only recommended the electric vacuum pump off a mid-'80's Cadillac (they were on gas and diesel cars). I was thinking about going with a Cavalier unit, but they said the Cadillac is the only unit with an internal pressure switch so that the pump only runs when necessary to add to the normal engine vacuum. It's a good thing, because most electric vacuum pumps are noisy so you wouldn't want one running all the time. The Cadillac unit is installed in the vacuum line between the engine manifold and brake booster. I was told the Cavalier unit only connects to the booster and runs all the time, but I can't verify that. Somewhere there is a thread on TC that a member provided all the cars and years that used electric vacuum pumps. Also, some Cadillac's used belt-driven pumps, so if you are calling the dismantling yards checking on parts, be sure to ask specifically for the electric units.
I used this pump and it works great!
I however didn't even hook it up to the eng. I used a vacuum can from Summit in conjuction with this pump so the pump comes on with the ignition switch and stores vacuum in the can and shuts off. When the can gets low the pump comes on to fill it again.
The part number I used was AC-Delco 215-119 from GM cost me about $200, weather pack connector $25. I fabricated my own mount.
Bob Tiley; I wish I'd seen that site when I was looking for mine.
Wes, You don't tee the pump into any line. The Delco pump has an inlet and outlet. The booster connects to the inlet and the outlet runs directly to the engine manifold. The instructions that came with the Delco vacuum pump said specifically not to tee it into any other vacuum line. It needs a dedicated vacuum line directly to the engine in order to "add" only the vacuum needed to boost the manifold vacuum so that there is about 21" of vacuum in the brake booster. The pump is only supposed to be a booster to the manifold vacuum, not the sole source of vacuum for the brake booster.
[This message has been edited by Hotrod65SS (edited 07-09-2001).]
[This message has been edited by Hotrod65SS (edited 07-09-2001).]
Rod; If I understand you correctly; A line goes from the manifold to the pump assembly, then another line goes from the pump assembly to the brake booster.
Is it possible that there is a check valve internal in the assembly?
I'm trying to get it clear in my mind that the pump isn't tring to maintain a vacuum on the manifold side of the pump assembly, but only on the booster side.
Technical Reference section
Gold Member #5
[This message has been edited by Wes V (edited 07-10-2001).]
Wes, I believe you are correct in your assumptions. There is a check valve in the vacuum pump that maintains the pressure on the brake booster side and not the manifold side. If you disconnect the hose from the pump to the manifold, the pressure will still hold in the system. In theory, you could use the pump as a stand alone to provide 21" of vacuum to the booster on a full time basis. Once the vacuum in the booster is achieved, the pump cuts off. The system, as designed, is intended to add only the additional inches of vacuum that your engine cannot provide. It will not increase the vacuum in the hose between the pump and the manifold above the actual manifold vacuum, only in the booster side hose. The intent is to not have the pump run anymore than is necessary to get sufficient vacuum for the power brake system. The supplier told me that the most demand for these electric pumps are on supercharged engines, where you have no manifold vacuum for the brake booster. Under that situation, the pumps are connected only to the brake booster.
I sure would like to see a picture to Indentify cadillacs or any other car that is supposed to have these pumps. I printed this info out and spent the better part of a day at the boneyard and did not find one single pump in any of the models noted in that web page. I found a buch of 12V air compressors but not one vacuum pump.
Big James, the following link to Master Power Brakes shows a picture of the Delco unit. The connection that is marked "vacuum out" connects to the brake booster. The other connection that looks like an annodized vacuum advance connects to the manifold and contains the pressure valve. I bought my pump from Classic Performance Products in Buena Park, CA for $250, but some places asked up to $350 for the same unit. I was told by CPP that the Delco units are not being manufactured right now. CPP only had two left a couple of weeks ago and will not be able to get new ones until they are manufactured again. http://www.mpbrakes.com/mp27.htm
Hope this helps.
[This message has been edited by Hotrod65SS (edited 07-10-2001).]
Thanks Hotrod! The thing is I took the web page I printed out with me and I knew what the pump looks like, I'm just frustrated that after looking at every Caddy, Cavilier, Pontiac, etc. said to have one that none were there, must have looked at 300 cars of all years and models mentioned also.
I don't need one now but for future projects I'd love to have one. The boneyard I go to is one of those shredder operations and the people there would probably sell one for $10/$20. I bought 4 12V air compressors for $20, don't need them but sometimes you just gotta have them anyway, besides, I could make a set up to pump up the air shocks on my elky at the flip of a switch.
Elcaminos are special!
I'd rather walk around with a Chevrolet hubcap in my hand than drive a Ford
That was the number I gave the parts counter guy and he produced the right pump. Some of the Caddies have a pump that runs full time. It has a 2 wire connector. This pump has a 4 wire connector. The shut off valve is built into the pump. Master brake sells the same one I believe but for substantially more $300 to $350, but I think you get a bracket for mounting. I made my own.
What I did was run one hose from the pump to a "vacuum can" then an other hose from the pump to the “check valve” on the vacuum can then from the can to the check valve on the booster. That way the pump stores vacuum in the can till it is needed. Then when it goes low the pump comes on to replenish the vacuum in the can.
I have nothing connected to the eng at all. If you do use eng vacuum I believe the manufacturer has a charcoal filter in line to keep gas fumes out of the pump.
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