GM Fuel Lines

[Ranger]

I know GM has a "special tool" for their quick disconnect fuel lines. I am about to tackle the infamous GM 3800 series II upper manifold leak. Believe it or not I have never had to remove a fuel rail yet. My question is, is this tool neccessary or is it doable with a screwdriver and pliers or something like that if I can't locate one?

[bigfoo]

They seem to have a special tool for freggin everything hehe

[Logan]

Larry, there is a plastic version of the tool. Its often included with new fuel filters etc. Should be easy to find one and worth using.

You know about the rotted 3800 plastic manifolds? It appears they will have to be replaced every 10 years or so. There are aftermarket ones available.

[Ranger]

Larry, there is a plastic version of the tool. Its often included with new fuel filters etc. Should be easy to find one and worth using.

You know about the rotted 3800 plastic manifolds? It appears they will have to be replaced every 10 years or so. There are aftermarket ones available.

Bigfoo,

Yeah, thats just what I was thinking.

Logan,

Thanks for the response. I'll try to find one.

I,ve been doing some research on those manifolds. Apparently the problem is the stove pipe touches the upper intake and burns through. Ken-Co makes an adapter that sleeves the manifold hole and gets epoxied in. It also comes with a smaller diameter stove pipe so there is no contact and has an air space between them, kind of like a double walled chimney pipe. Once I get it off I will look at it and if not in too bad of shape I will custom make my own adapter. If you look at Ken-Co's site http://www.ken-co.com/manifold/default.htm you can see that it makes a lot of sense and is quite simple and easy to make. J B Weld should work well for the epoxy as it is good to 500 degrees. Ken-co wants $80 for this adapter. I figure I can make one for less than $5. I think this would be a permanent fix. I will probably do it even if I have to replace the manifold. What do you know about the lower manifold gaskets? Do I need to replace them as well? There doesn't seem to be a problem with them but guys on a Bonneville forum are saying replace them as well. One guy even had a catastrophic failure of the lower as hard as that is to believe. He said it dumped his entire cooling system into his crankcase

[Logan]

I dont think the plastic intakes are worth fixing. They have problems with rot from the hot coolant passages and EGR gases.

I know Dorman is one aftermarket manifold that is available.

http://www.northernautoparts.com/WhatsNewD....cfm?StoryId=57

And yes.....failure will dump coolant into the crankcase. It maybe possible....to install the older '92-93-94 (?) metal intake and really be done with the issue.

[shiden_kai]

I,ve been doing some research on those manifolds. Apparently the problem is the stove pipe touches the upper intake and burns through. Ken-Co makes an adapter that sleeves the manifold hole and gets epoxied in. It also comes with a smaller diameter stove pipe so there is no contact and has an air space between them, kind of like a double walled chimney pipe. Once I get it off I will look at it and if not in too bad of shape I will custom make my own adapter. If you look at Ken-Co's site http://www.ken-co.com/manifold/default.htm you can see that it makes a lot of sense and is quite simple and easy to make. J B Weld should work well for the epoxy as it is good to 500 degrees. Ken-co wants $80 for this adapter. I figure I can make one for less than $5. I think this would be a permanent fix. I will probably do it even if I have to replace the manifold. What do you know about the lower manifold gaskets? Do I need to replace them as well? There doesn't seem to be a problem with them but guys on a Bonneville forum are saying replace them as well. One guy even had a catastrophic failure of the lower as hard as that is to believe. He said it dumped his entire cooling system into his crankcase 

If I were you, I wouldn't bother trying to repair the upper plenum. I've seen the kits that you described and "if" you caught the problem early, you might be able to effect an ok repair with the kit. I don't have a problem with the smaller tube that is inserted into the lower manifold....GM does this automatically with their changeup manifold that has been released. Personally, I think that it's a huge waste of money to replace the entire lower manifold just to get the smaller diameter tube.

But again, I wouldn't bother trying to repair the upper. The problem is not only that the EGR tube burns a hole through the manifold into the water jacket, it also warps the entire manifold at the rear by the throttle body.

You should replace the lower intake manifold gasket. They are made of the same basic materials as the infamous 3100/3400 gaskets. They do not have quite the same problem as the 3100/3400, but this is due to the different designs of the engines and where the coolant passages are located on the two engine styles.

But, I have pulled many lower manifolds and found that the gasket has begun

to split around the coolant passages. Why take a chance, you are almost there once you have the upper plenum off.

Depending on the year, there are two different design lower gaskets. The difference is at the end seals, but it's significant enough that you want the right one. It's also very obvious.

Ian

[Ranger]

Thanks for the advise Ian. Not what I was hoping to hear but better now than later. Guess I'd better start searching for a manifold & gaskets. Oh yeah, and that "special tool".

[shiden_kai]

Thanks for the advise Ian. Not what I was hoping to hear but better now than later. Guess I'd better start searching for a manifold & gaskets. Oh yeah, and that "special tool".

You should be able to find those fuel line release tools pretty much anywhere for just a few dollars. I bought a set which are simple plastic ones, have been using them for years, they work great.

Ian