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Discussion Starter · #1 ·
Hey, I can't shut off the 300d right?, so, I try to hunt down the loss of vacuum, and
I encounter these matters:

1. the plastic valve on top of the valve cover thats trans. related (5-6 little vac. hoses under the cover) doesn't hold vacuum, anywhere. I used the vacuum pump to push smoke through it and it came out the back.

2. the plastic job next to the alda on top of the injection pump holds no vacuum on the bottom port and drops vacuum in 3 seconds from the top port

3. I noticed a line from the front of the vacuum harness on top of the valve cover that goes through a Tee to the plastic on the inj. pump, and then through the firewall, once inside the firewall, it is wide open, with no attachment.


and yes, I was trying to do preventative maintenace and replace some hoses, and
I'm guessing I f-dup,

SO... Are numbers 1-3 normal? (probably not huh?)

any suggestions? Much appreciated

Nick
 

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1980 300D
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309 Posts
On my 1980 300D I replaced EVERY white plastic vacuum thingamajig and EVERY rubber connector under the hood, especially the connectors to the dreaded heater servo in the right front of the engine compartment. The white plastic valves on top of the cam cover and the fip-just replace. The hose to nowhere is supposed to be just that - leave it alone. Check your brake booster to see if it holds air. Welcome to the vacuum mystery lifestyle.
 

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Discussion Starter · #3 ·
I'm going to assume that all of these components are meant to hold vacuum, and
therefore, most are bunk. My shut off valve is solid, also brakes are good, sink a little at long lights, but nothing scary.
Anyone know where the vacuum valves off of the cam cover and vacuum control valves are for sale?
 

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1980 300D
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Get the new valves from the dealership nearby - they are inexpensive and the highest quality and once replaced should last a long time. However, be sure to check them for leaks before you leave the parts counter - some leak when new, especially the valves on the cam cover. Be sure to check the egr valve. If you are having a vacuum leak your brakes should be getting HARDER at a light, as the vacuum leaks. Check your booster, the tend to rot in the back on the bottom. PERFORMANCE PRODUCTS has lots and lots of the parts but sometimes don't match the factory specs...
 
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