Vacuum Pump Leak at Head

[ngoma]

Leaks pretty good where the vac pump connects to the cylinder head. 13mm Connecting nuts are tight. Did some searching and am suspecting it will need a new o-ring seal. Does anybody have a source? Looks like I will need to rotate the engine to TDC to reinstall the vac pump, to allow the plunger rod to return.

V8volvo, I may have bought one of the cars you wrote about earlier. Was one of them the Marble car?

[IceV_760]

Its not necessary to turn it to TDC to fit pump back.
Its just a "bit" tighter to place when nose-axles peak is on wrong place on wrong time, and if you feel so just randomly turn engine. Roughly 270*deg. out of 360*deg. you should be able to place it easily.

[Jason]

I checked our listings and I don't see it unless you get the gasket set. You could try tasca.

Jason

[ngoma]

Thanks for the speedy replies. If it is indeed an o-ring, I could probably bring it to a local warehouse (Tacoma Screw?) and have them measure/ match up a replacement.

[v8volvo]

The part is an oval-shaped O-ring. Available through Volvo, it costs about $7. Or you can take the old seal out and bring it to an auto parts store and get any round O-ring that is the same size. A round one will work, but it is more difficult to install than the proper oval one from Volvo, since it will want to jump out of the recess where it sits when you turn the pump vertical while installing it. Use a bit of light grease (assembly lube or Vaseline are ideal) to hold it in place as you install and it will work fine. I use the genuine Volvo product since it only costs a few bucks more and I know it's right, but I'm a perfectionist and it's not really necessary...

Tacoma Screw would probably have something that would work, just make sure it is an automotive or marine product because it needs to be able to stand up to oil and high temps. Many kinds of rubber will break down when exposed to those factors.

A tip: do NOT use any RTV or other sealant when reinstalling the vac pump. If the O-ring is good, sealant is completely unnecessary and all it will do is make a mess. If there is already some on there, as there usually is from some past mechanic being an idiot, then clean it off and install it dry with just the O-ring. You don't want bits of squeezed-out sealant getting down that oil drain hole in the head and ending up somewhere inside the engine, blocking oil flow.

It is easiest to install when the engine is at #1 TDC since you don't have to fight spring pressure to get it back in. Also try to ensure the plunger gets installed back in the same way it was before, to prevent excessive wear of the cam lobe that drives it. Easy to find #1 TDC by looking at the pulley on the injection pump and roughly matching the notch in its rear flange up with the notch on the pump bracket. It doesn't have to be exact, just getting it close will make the job much easier.

ngoma I assume you are located in the Puget Sound area... what is the Marble car? You'll have to jog my memory...

[v8volvo]

If you get the complete cylinder head gasket set, for instance the Reinz one that IMC sells, it does come with the seal for the vac pump, but it uses a round O-ring, not the oval OEM-style one. Not a big deal but it is a slight difference.

[ngoma]

Originally Posted by v8volvo

ngoma I assume you are located in the Puget Sound area... what is the Marble car? You'll have to jog my memory...

Last (2) owners name were Marble, the father (Lopez Island) passed it along to his son (W. Seattle). Anyway, it's sky blue, now has 173,xxx miles, was thinking it was the 157,xxx car you were describing for sale last June?

Trying to sort out the misc. issues:
Oil leaking from vacuum pump.
Leaky injector jumper hose #3-4.
Worn PS pump mount bushings.
Shakes (misses?) at idle and off-idle.
Excessive smoke at WOT/hi revs.
Failing u-joint that growls on windup.

I already fixed the starting problem by replacing GPs #1, 2, and 3.

And brought the coolant temp gauge to life by plugging it in to the correct temp sensor next the GP #1, and moving the GP controller brown temp sensor wire to its correct sensor at the rear of the head, below the cam sprocket. Will need to run new wire for the deteriorated coolant sensor wire, and also the oil pressure sensor wire.

I feel I can get a handle on things if I can find a good supplier; I like to support local-- any place you recommend here in Seattle?

[Jason]

Might try running some quality injector cleaner through it to help with the missing, assuming they aren't leaking. I ran the BG 244 and it made a very noticable difference. With the miles, it may just be time for rebuilt injectors though. Check your boost to see what its making for the high rpm smoke. The injection pump may have been adjusted possibly incorectly as well.

Jason

[ngoma]

Jason you may be onto something. Maint. records show no evidence of injector rebuild or replacement, 173,xxx miles is plenty for orig. injectors. Should be fun to pull them out. Car came with a clean reman injector (tag states 155 Bar) and heat shield in a Volvo Remanufactured Part box in the trunk, along w/ some green books, orig. manuals, service receipts, etc. and 5 fresh Mahle oc105 oil filters.

I'll see if the local Bosch shop has heat shields, and also a repair kit for my old Bosch pop tester. The gauge shutoff valve drips out the shaft and the pump is tired.

Cleaned/matched injectors might help the idle miss and smoke.

Don't have a way to check the boost but the fuel delivery screw has been tampered with-- tamper seal is gone, and the yellow paint is chipped away from the screw and locknut. Feeling I had nothing to lose, I have turned this screw out 1/4 turn which seems to have cut down some of the excessive smoke, I don't know if this has affected the timing. Experimentation cut short by a progressively worsening injector return jumper line leak.

The previous owners had tried to maintain the car well. They spent plenty of $$$ at the shops, but I think some of these shops didn't fully understand the quirks of the d24t and so unknowingly sabotaged it to some extent.

V8volvo, if you are available for a consult I would like to bring the car by to get your opinions.

[Jason]

My car has right around 170k miles and the BG really made a difference. I was going to buy rebuilt injectors but once I ran the BG through it, and have just been running the crap out of it in general, it has really smoothed out... Enough to where I'm leaving them in.

The full power screw wont affect timing, you also may want to look at the depth of the allen head screw and jamb nut on the top of the afc housing on top of the pump. If its been bottomed out, loosen the jamb nut and unscrew the allen head bolt untill it stops, then snug the jamb nut again. With the correct injection pump settings, the factory level of boost should totally clean up the exhaust under full throttle and full boost. I would keep turning the full power screw out 1/4 or 1/2 turn at a time, you will probably have to adjust your idle speed up a little to compensate. I would recomend driving it between adjustments, as you reduce the fuel quantity obviously you are going to loose power, you may find that putting up with a little smoke may be worth it for the extra power to get out in traffic!

Jason