valve cover gaskets

[leenigen]

I have a '94 with a 6.5NA that's leaking oil badly from the valve cover gaskets. At first it was a mild annoyance but it seems to have gotten worse. In order to change the gaskets it looks like I'll have to remove the injector lines. What problems could that cause me? I'm worried about restarting the engine - not to mention broken injector lines. How hard is it and what's the process of restarting the truck when the injector pump has essentially been drained of fuel?

[phazer42]

well there are two schools of thought.... On my Humvee, 6.2L NA I never removed the injector lines completely, I was able to bend them out of the way enough to get the valve covers out - being very careful not to damage the lines, they are rather thick....

The other is to remove the lines from the IP which is a big job and you need to mark the lines where they came from or you could have roubles during re-assembly.

The lines themselvers don't hold much fuel at all so I never have had any problems starting after they were drained. If you do, what I did was removed the feed line to the IP and then cranked until I had fuel, and then re-installed it while I was cranking which allowed me to start the truck up without any air bubbles.

If you haven't already, you might also want to familiarize yourself with the www.humvee.net forum.....

[leenigen]

So you're saying disconnet the lines at the injector side and carefully bend them up? That had crossed my mind. Did you use a tubing bender or any other method to avoid kinking the lines?

[Yetti]

you do not have to use a tubing bender. you are not reshaping the lines, just moving them up out of the way. I suggest you take the line clamps off on the intake side so they lift a little easier. secondly the reason your gaskets are leaking is because you are not pulling a crankcase vacuum. most like the resperator is not working. either its plugged with sludge or the hoses & seals are cracked and leaking. check where the hose attachs on the sides of the intake and make sure its all there & working.

when you remove the lines from the injectors make sure you gaurd againest dirt getting into the injector opening. use plastic caps or something to keep the dirt out.

[leenigen]

By resperator do you mean the CDR valve? I checked the vacuum a few months ago using a gauge connected to the dipstick tube...0 at idle 3-5 at ~50mph depending on rpm . I thought that might be a little low but i think it's about what I read it should be.

[phazer42]

yes, he means the CDR valve.... however if the truck is older, it can dry rot the gaskets, especially if the truck sat for a good length of time. I don't recall what the numbers are for the venting, but a new CDR doesn't run that much...

if ya need help one weekend let me know I am not toooo far from ya, Iam in Waterford in the middle of Oakland County.....

[pdsq99f4]

Whatever you do, don't use cork gaskets that you get from the parts stores. I use silicone rtv.

[ssgharkness020147]

Originally Posted by pdsq99f4

Whatever you do, don't use cork gaskets that you get from the parts stores. I use silicone rtv.

RTV failed on my truck once. Hopefully this time its better.

[Yetti]

as for Gaskets. The GM Black RTV was the best at holding. you have to scrub down the rails and get every bit of old gasket off with a wire brush and carb/brake cleaner. I used to take a drill bit and clean out the bolt holes so as to not crack the head when putting the new gaskets on.

CDR...yea thats it, I couldn't think of the name. I once had a 5.7 diesel that was leaking 6-7 quarts a day in a Caprice. me and my buddy did some figureing and created a SUPER CDR. we used a length of vacuum hose on the intake snorkle to find the peak vacuum at crusing speed. we then welded a peice of tube into the snorkle and on in the oil filler neck. we dropped oil cunsumption down to 1 quart a day by tuning it in.

if I remember right the GM RTV comes in a caulk gun tube for around $40. you might find it cheaper at the parts store.

[leenigen]

Phazer42, I'm taking next week off and plan on working on the truck most of that time. I can take care of the repairs myself but if you want to come down and play on a weekday send me an email at LEenigenburg@Arcadis-us.com.