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-   -   What should a vacuum pump check valve look like (http://www.peachparts.com/shopforum/diesel-discussion/313853-what-should-vacuum-pump-check-valve-look-like.html)

sleepstar 03-03-2012 05:27 PM

What should a vacuum pump check valve look like
 
ok maybe a stupid question, but i've tracked down a vacuum problem to either the pump or check valve.
i have an 81 300D with the newer style, single outlet pump. i pulled the valve and hose off today, the hose is fine. the valve though, i'm guessing it should have some kind of internal structure? mine is right now, basically just an empty fitting.

my symptoms are 5-10" of vac at cold idle, once the motor has been running for about 20 minutes, full 24" vac. it's causing the trans to shift like garbage for the first 20 minutes of driving. would a bad valve cause this or should i just look into getting a pump.

also since this is the newer style pump i'm also assuming i dont need to worry about it self destructing into the timing chain right?

Diesel911 03-03-2012 05:31 PM

Trace your Main Vacuum Line to the Vacuum Pump, The Check Valve is the Fitting the screws into the Vacuum Pump Body and the metal Tubing of the Main Vacuum Line screws onto the Check Valve.

If you want to see a pic check one of the internet part Sellers.

sleepstar 03-03-2012 05:33 PM

Quote:

Originally Posted by Diesel911 (Post 2895468)
Trace your Main Vacuum Line to the Vacuum Pump, The Check Valve is the Fitting the screws into the Vacuum Pump Body and the metal Tubing of the Main Vacuum Line screws onto the Check Valve.

If you want to see a pic check one of the internet part Sellers.

yup, i pulled that valve off along with the hose. the hose held vac fine. but the check valve doesnt really look like a valve. it's completely empty inside. it's just a hollow brass fitting at the moment.

tangofox007 03-03-2012 06:22 PM

Quote:

Originally Posted by sleepstar (Post 2895469)
but the check valve doesnt really look like a valve. it's completely empty inside. it's just a hollow brass fitting at the moment.

That would be because the retainer plate rusted/failed and dumped the check valves components into the pump inlet. Time to go fishing. You want to find a spring, a plunger, and a retainer plate.

sleepstar 03-03-2012 06:42 PM

Quote:

Originally Posted by tangofox007 (Post 2895487)
That would be because the retainer plate rusted/failed and dumped the check valves components into the pump inlet. Time to go fishing. You want to find a spring, a plunger, and a retainer plate.

wow that suckkkkks. do you think i can do this with the pump still attached to the motor? any chance these parts have been shredded inside of their already?

sleepstar 03-03-2012 07:36 PM

ok with some more focused searches on here i've learned the valve pieces are too large to actually fall completely into the pump, so im not worried about that. but i wonder if this failed valve is still the cause for low vac when cold, but full vac when warm. gotta replace it anyway i guess.

tangofox007 03-03-2012 07:40 PM

Quote:

Originally Posted by sleepstar (Post 2895522)
...i wonder if this failed valve is still the cause for low vac when cold, but full vac when warm.

Intermittent vacuum is the typical symptom. My guess is that the valve components rattle around in the pump inlet and intermittently block air flow into the pump.

Diesel911 03-04-2012 02:00 AM

You need a Good Check Valve to hold the proper Vacuum. I had a Vacuum Issue and removed my Check Valve and sprayed it out with WD-40 and put it back on and it worked fine after that. And, yes my check valve was not hollow.

The Check Valve is slightly expensive. I do not see why one from a Junk Yard would not work if you take a look and see if the parts are inside and still good.

toomany MBZ 03-04-2012 10:32 AM

1 Attachment(s)
I have a pdf laying around, this page should be of help.

tangofox007 03-04-2012 11:19 AM

Quote:

Originally Posted by toomany MBZ (Post 2895772)
I have a pdf laying around, this page should be of help.

Wrong check valve.

sleepstar 03-04-2012 11:28 AM

yeah, bad title at this point. should have said "what should the inside of a vacuum pump check valve look like"

tangofox007 03-04-2012 11:42 AM

Quote:

Originally Posted by sleepstar (Post 2895793)
yeah, bad title at this point. should have said "what should the inside of a vacuum pump check valve look like"

There are three more check valves inside the pump.

toomany MBZ 03-04-2012 12:29 PM

1 Attachment(s)
The pdf is a generic diagnosis, yet the instructions should tell you if the valve is operating.

tangofox007 03-04-2012 01:44 PM

Quote:

Originally Posted by toomany MBZ (Post 2895823)
The pdf is a generic diagnosis, yet the instructions should tell you if the valve is operating.

1. That check valve has nothing to do with the brake booster.
2. If the "guts" of the check valve are missing, no further diagnosis is required. The check valve cannot possibly operate.

tangofox007 03-04-2012 01:47 PM

Quote:

Originally Posted by sleepstar (Post 2895494)
wow that suckkkkks. do you think i can do this with the pump still attached to the motor?

Try a vacuum cleaner at the pump inlet port. The plate and spring are magnetic, so a magnet might be somewhat effective.


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