Isuzu I-Mark diesel

[truckinwagen]

well, it feels good to be back in my car again!

now all I need to do is figure out why my mileage is on a downward spiral, it was 30MPG when I got the car, but has been declining recently, last tank was at 22MPG...

I think its a fuel leak, but am not sure about lying under the car to check for one in this cold...

-Owen

[truckinwagen]

well, just parked it on some pavement(the only good use for parking garages, no snow in the winter!) and let it run for a while, no drips(was kinda expecting a fuel leak considering such a large drop in MPG)
which is good, no more oil leak, no trans leak etc...

next on my list is to get the rear end up on jackstands and see if the u-joints are still good, as well as feel for bad bearings in the rear end(dont hear any of the telltale sounds of rear end trouble, but you never know)

I will also take the crap out of the trunk to see if dropping a few hundred pounds would help.

-Owen

[truckinwagen]

well, I am looking into an electric vacuum pump for my brakes now that I have eliminated the stock one on my car.

what do you guys think about one of these:
http://cgi.ebay.com/ebaymotors/Saab-Brake-Vacuum-Pump-900-9000-9-5-9-3-9-5-9-3-4646220-/380292258903?pt=Motors_Car_Truck_Parts_Accessories&hash=item588b2f5c57#ht_500wt_1182

or what about the electric vac pump from newer VW's?

also, I am having trouble finding vacuum operated switches to control it(dont really want the pump running all the time, so I want to shut it off when enough vac is reached)

-Owen

[maxfax]

GM used one in the 80's to control the lock up torque converter on non computer controlled vehicles..  GM #14014519 and found on the '83-'85 S-10's with a 2.8 and auto trans..
  
IIRC though I think they are normally off until the vac reaches around 10" then it turns on, it would work bass ackwards..

Some of the vac operated 4x4 getups use vac switches to run lights (84-86 Cheokee and a few more years on the Wrangler), but again I think they work backwards..  

Of course it would probably be wise to use a relay to run the pump.. IF you went that route you would have sort of a fail safe setup.. IF the switch fails, or fuse blows on the control circuit the pump would always run...

[mr.woods]

http://www.mcmaster.com/#vacuum-switches/=abdhxa

Or what does the ford 7.3 stroke use? I know they have a electric pump.

[theman53]

Since you are making brakets you could use an old hydraboost.

[R.O.R-2.0]

hydroboost out of a mid 80s GM pickup?

still gotta have a power steering pump, and funky brake booster..

[theman53]

yep. When working still my favorite brake setup. Since he is making brakets and is good at doing that, it "might" be an option. I have no clue what fits what, but that maybe sweet.

[truckinwagen]

well, I would like to keep the number of spinning accessories to a minimum, and sourcing a complete working hydro booster would be difficult, and probably more expensive than getting and setting up a electric vac pump.

also, having vac would be nice, as the bypass valve on the supercharger I am using can be activated by vac or boost, which would allow me to bypass under boost from the turbo, as well as be able to bypass manually for cruise(to maintain fuel economy)

as for a control circuit, I would make it to fail in the on position, so if something goes wrong I will still have vac.

there are lots of options for vac pumps used to supplement power brakes, I guess my question is do you think they would be up to the task of running the brakes all by itself, or would they burn up?

also, the switch to trigger it is still a problem.
I could get another auber gauge to control it, but that would be pretty spendy.

-Owen

[81 vw pu]

Here's a little info on where to find used vac pumps with on/off switch built in.

http://www.gmcmotorhome.com/tech/vacuum_pump/index.html

[truckinwagen]

excellent!
thanks for that info!

-Owen

-Edit-
but that part number appears to be for a belt driven vac pump, not an electric one...

[maxfax]

When working

That right there is the key point..   They are great when they are in good order, my 70's Lincolns all had it..  3 tons and they'd stop on the proverbial dime..  But there's also a delightful pile of crap to leak...


Owen, as long as you have no leaks those electric pumps should be just fine..  Unless you pump your brakes a lot or something like that...

[truckinwagen]

found a switch!

and its only $30!
http://www.evparts.com/products/street-vehicle/brakes--dot/switches---street-vehicle/bk2785.htm

gonna find a good vac pump now...

-Owen

[mr.woods]

I could see problems with an electric vac pump. I would still think about a Hydro-booster. They are small and cheap. We got complete units out of scrap yards for next to nothing. I ran them in all my offroad trucks till the newest one, that will be full manual.

What about the electric brake boosters the new cars and trucks have? I've already seen '03 chevy trucks that have them in the scrap yards

[truckinwagen]

one of the reasons I am leaning toward the vac pump is that it would be a quick install with little fab work.

I cannot afford to have the car off the road right now, so if I dont have to pull the booster I dont really want to.

-Owen