My thermostat stuck on my 91 last week on my way out of town, (when else would it happen?)
I heated up to about 3/4's on the guage for about five minutes.
I had a local shop change the thermostat only because I was leaving town- got to take my wifes 98 instead- and almost $400 later they gave me my truck back. OUCH!!!
Here's the problem. The radiator now gets super pressurized as soon as you start the engine and spews coolant out of the overflow. The shop said that either the head is cracked or the head gasket is blown. ( they want over $1000 to replace the gasket)
I seriously doubt I got it hot enough to crack the head, but is that possible?
Also, has anyone replaced the head gasket on one of these and have any hints?
I have to do the work next weekend and want to be ready for whatever.
ANY help is appreciated!

 

A headgasket job is pretty straight forward and easily accomplished. Make sure you have an a-frame or a cherry picker to lift the head out. I believe the head is close to 130lbs.
It would probably be a good idea to get the head fluxed .
Your going to have to remove the injector lines so it would probably be a good idea to get new copper return line gaskets. I believe the B series upper gasket kit will come with these. Be sure and inspect the head bolts real good. Check for pitting or corrosion on the bolt as well as the length of the bolt. Clean the block surface up REAL good as well as the head combustion deck.

the short bolts max length is 2.815 in, medium bolts are 4.807in. and the long bolts are 7.201 in. IF you find any over this spec. Throw them away and get new ones. Have a good torque wrench (click type preferably) on hand. The torque of the head bolts are a 3 step plus 90 degree turn.

 

It's an easy chore once you get over the "Oh God, what am I doing" phase!

Just did it a few months ago. You either blew the gasket or cracked the head. Since you have a 91, is it an early 91 or late 91 (non-intercooled/intercooled)? Early non-intercooled heads were prone to cracking between the valves. due to a less than adequate amount of material due to the larger injector tips.

Like Monty said, a engine lift is almost a necessessity for removing the head. I would have a spare set of hands for removal. Putting back on is an easy one person job. Your top end gasket set from Cummins (BUY ONLY CUMMINS HEAD GASKET SET), will have all your copper parts necessary. You will need a set of old style valve seals though if you are going to have any head work done. The set that comes with the kit are for shimming up your valve springs. They look like powerjoke valve seals.

Goog luck, have fun and enjoy learning a little more about your truck!

Carl

 

Thank's, that helps. Seeing as I won't be able to get parts while I'm working on it- Not much chance of local parts places having what I need, do you think I should just get the bolt set while I'm at it?
Are the bolts usually in pretty bad shape?
Is cummins the best place to get parts, or dodge, Napa, or anyone?

 

Early 91- non intercooled
Thanks for your suggestions

 

If it were me, I would go ahead and get a set of bolts. Due to the age of the truck and the fact that they arent very high. Skip NAPA or any other chain parts stores. Dodge is going to get the parts from Cummins and tack there price on top of that. If you can, get all of your needed parts from Cummins. Be in there once with the right parts and be done with it.

 

It took me four tubes of that blue silicone stuff to get my head sealed up. I think I would just that gasket material next time instead of one of those expensive cummins things. .

I would recommend buying an entire bolt set. There are 26 of them. They call the long six rocker pedistal bolts. If the head is not cracked, be sure it is flat and have it decked if necessary. Using a quality torque wrench can save some headaches also. I saw a head torqed with a fairly new Craftsman wrench a while back- it ended up leaking due to improper torque. A razor blade can make cleaning the block easier. Also, be sure to get all of the oil out of the bolt holes in the block. First gens are easier than second gens. Enjoy the extra space!

Mike

 

Thanks guys. Where would I get the torque specs and pattern for the bolts? would cummins have these?

 

They might be nice enough to make a copy of that page of a service manual.

 

got the head off last weekend.
blown gasket, as I thought.
I had the head checked, and he found a couple SMALL cracks between the injector holes and the intake valves.
I talked to cummins tech and he said this shouldn't cause a problem.
hope so. I'm going to put it back together and hope for the best.
I can't afford a new head right now.
I'll let you know how it turns out.

 

The non innercooled engines were made with larger bodied injectors and were changed later due to the possible cracking. I haven't seen any of these myself, mine seems ok, no head gasket leak yet. I would take every precaution with cleaning up the studs to reduce the chances of cracking it worse on installation. I hope that if anybody else tried to re-use one will let us know. You might look into getting a cross flow radiator from another vehicle that is a close fit to your verticle flow. This might help stabilize your cooling so you don't get spikes in your engine temp that would cause the cracks to grow. A 92-93 rad. would require a little carving in the core support. I would still prepare myself for a new head down the road. Get a 2nd gen head, I don't think the price diff. would be very noticeable.

 

Got it all back together finally. Actually last weekend, but I just moved also, so I couldn't get back on here.
The head seems to be working just fine with those cracks. No apparent problems anywhere after about 500 miles so far.
I did have to adjust the valves, as they milled the head .016 to get the warp out!!
Thanks for all the help guys.
Now on to rebuilding the vaccuum pump.......