Got an electric vacuum pump?

[Bristol]

Was wondering if anyone has an electric vacuum pump used to build vacuum for power assisted vehicles that I could borrow or rent so I can try to diagnose a poor braking issue. They are like $300 so Id rather borrow or rent a unit rather than buy one only to find out it doesnt solve my issue. If anyone has one, or has any suggestions brsides converting to a hydro boost system please let me know. Appreciate any assistance. Thanks

Kris

[MonkeyWrench]

have you tried a manual vacuum pump on the booster to make sure its not leaking?

[Bristol]

Yup. Holds pressure fine. Only getting 13" in park fully warmed and 11" at an idle of 650rpm. Replaced booster line and 1 way valve...no change. No vacuum leaks found and idle drops as it should from park to drive and with the 650rpm idle indicates no leaks. Fairly smooth vacuum gauge also indicates no leaks. Plugged all vacuum ports and still same reading. Blead brakes and good flow and no visible air pockets. Added a Comp Cams vacuum resevoir and still crappy brakes. Alot of guys that have big cams and run low vacuum seem to be ok with a resevoir but not in my case. You get 2-3 ok pumps with assist and then pedal goes hard as if theres no boost. With the first 2-3 pumps even if 2 footed car slowly stops. Not anywhere close to a lock up. Basically I wanna borrow a electric pump which turns on to maintain a booster pressure with a minimum 18". Then I can verify if its a vacuum issue and not a mechanical failure.

[Bristol]

Oh and Im gonna measure line pressure to each caliper and was wondering if anyone knew what pressure it should be. Thanks

[Ta88gta]

Same problem i had in my TA. Downshift the car and it will give you more vaccum, then see how the brakes work. Basically does the same thiing as the pump. If they work when you down shift then get the vac pump

[allpontiacs]

Dude, you can pick these things up for next to nothing at the wreckers. Goolies and shit from the 80's had them. Chances are the guy at the counter won't even know what it is, so use that to your advantage.

[Bristol]

Funny you say that...got a beater 89 6000 LE in my garage that I was gonna do a head gasket on.....how hard is it to add in

[allpontiacs]

Pretty easy, just hook up a vacuum line to the booster and wire them up through a switch. Zap-strap it up somewhere and you're set to test your brakes. My cousin had a pair out of some Caddy, they worked sweet too but the idiot wound up using them as tire chocks.

[89vert]

is it a hard pedal and weak brakes or normal pedal and weak brakes

[Bristol]

It starts off as a normal pedal for 3 pump with crappy braking to hard pedal and still crappy braking. I used to be able to lock them up and now I cant even come close on two foot stops

[89vert]

It starts off as a normal pedal for 3 pump with crappy braking to hard pedal and still crappy braking. I used to be able to lock them up and now I cant even come close on two foot stops



fluid comes out the all 4 bleeders?

does it come out hard?

can you lock the wheels with the the wheels in the air?

[89vert]

when did the problem start with the new cam?

[Bristol]

A little with the cam and more so with the HSR. Ive verified there are no vacuum leaks. Had a few guys ((mechanics)) confirm the no vacuum leaks. Cam isnt big ((08-305-8 and1.6 Gold Crane roller rockers))and car runs reasonably well with no tuning whatsoever

[Bristol]

Fluid looks good flow wise but want to measure line pressure. As for locking the brakes while in the air....fronts I can and rears I cant which according to TGO is normal?

[89vert]

I trhink your right about not enough vacuum,

I'd run with your electric pump idea,

I know a buudy of mine put a big cam on his carbed 3rd gen and his brakes fucking suck

[Bristol]

Well the 6000 LE doesnt have a pump from what I saw. Hose from the booster to the intake manifold. So would anyone have an electrim vacuum pump that I could borrow or rent. I dont wanna spend money on a unit to only find out its not the problem.

[Bristol]

Well does anyone know of a very good, trust worthy and talented shop that could confirm my brake issues?

[MonkeyWrench]

you should just red neck it up and get a power inverter and a shopvac

[Bristol]

Just a bump to see if anyone has any suggestions to be 100% sure it is infact a vacuum issue before I dump a bunch of money on a pump or does anyone have a pump from whatever car I can borrow?

[MonkeyWrench]

don't want to go with the shopvac eh?

[Bristol]

If you think it will really work Ill try it. Just thought it was a joke.

[MonkeyWrench]

to be honist with you i don't know what kind a vacume it would make but if you got a gage you would beable to tell. might be enuf. just get some duct tape and do it in your drive way not much to lose but 1/2 hr and 50 cent in tape

[383TA]

I'm running 11 inches of vaccum in my 350 S10, brakes work great.....

[Bristol]

11"s in drive at idle? Whats your idle speed? Drum and disc?Ive pretty much verified that its low vacuum and am attempting to cure it with a bump in idle speed through PROM tuning. I drove some hills and on the down slopes I let engine braking happen and at that point the vacuum created made my brakes feel very good. Thanks for the input.

Kris

[age]

Bristol: If it really started to do it after the HSR... I'm wondering if maybe you forgot anything during the install. Did you go over all the necessary vacuum lines that need to be plugged in the HSR?

I'm just trying to piece together the time line of things here... you didn't have this problem before.. then it started with the cam, and got worse with the HSR.

You've done whatever you could to locate any leaks, bled the brakes, check the booster/master cylinder..

It's either that you forgot something, or your prom needs to be tuned...or both

[383TA]

idle is at 850 rpm in neutral (manual). Yeah, its rear drum.
You sure you dont have a vacuum leak? Do you have any blowby?



11"s in drive at idle? Whats your idle speed? Drum and disc?Ive pretty much verified that its low vacuum and am attempting to cure it with a bump in idle speed through PROM tuning. I drove some hills and on the down slopes I let engine braking happen and at that point the vacuum created made my brakes feel very good. Thanks for the input.

Kris

[Bristol]

If my idles at 850rpm Id have no issues. Thats what we are doing right now...correcting the idle speed as 625-675 is way to low for my cam. Definetly no leaks. Rpms drop as they should from park to drive. Ive used propane around all seams and no idle change. Disconnected all vacuum lines and plugged all ports still no change. At this point my tuner says its cause of the stock tune and low idle.

[age]

Bristol, I'm really interested to know your cam specs...

[Bristol]

My cam is the Comp Cams 08-305-8

Its not big but is causing me issues. Comps tech dept. told me in needs tuning and to talk to their tuning dept. at F.A.S.T..

[age]

yes, I can definately see that now, and your idle is definately too low for that cam. What kinda roller rockers you using?

[Bristol]

Crane 1.6 gold rollers

[age]

ditch 'em.. go for the Comp Cams pro magnums... or at least get those the next time around (yes.. that's a big hint on what might happen to your cranes).

[Bristol]

Not really sure what you mean?

[age]

aluminum roller rockers will need to be replaced (if they're not rebuildable) in the future.

The pro magnums are completely rebuildable.

I've known one guy that's had to replace his crane aluminum rockers (not sure exactly which "model" he got) but he had a late 80's IROC. Karl has also recommended against them citing the same reasons..

I'm sure people have had good luck with them.. and there's no denying the gains in an aluminum roller rocker. Just a forewarning.. that's all.

[Bristol]

Oh...Yah I know they wear but they all do. Not concerned with rebuilding them...for the price I paid Id rather just buy new anyways. I spoke to Glenn a couple times about this. Thanks for the input.

[age]

<phew> ok.. good. I'm glad that you were aware of it. I didn't want you to be a victim of bad advice from a poor salesman