Just wanted to relay my experience in replacing the caps and o-rings. I have a 1986 F-250 3/4 ton 6.9.

I had one cap that was leaking pretty badly, so I went to my Ford dealer to get replacement o-rings. You can't buy then individually. They come in a kit of 16 only for about $16. When I went there, the guy recommended that I replace all the caps, lines and o-rings as when one goes the rest usually follow. So I bought a kit with the caps, o-rings fuel line and clamps for about $50. Pretty reasonable I thought.

I started replacing caps, and did an entire side. It's pretty simple to do. If you kind of squeeze the o-rings, you can get them off pretty easily. When I put the new ones on, I coated them with a small amount of motor oil. The cap when right on without any forcing required.

So after doing one side (4), I started up the engine and 3 out of 4 were leaking! Damn! I had read somewhere (probably here) that the guy put another o-ring on the bottom of the cap. So I put an old o-ring on the injector post past the 2 new o-rings, put everything back together and everything is dry as a bone!

So my advice to anyone taking this on... just get the o-rings and replace just the ones that are leaking. And use one of the o-rings on the bottom to save yourself a step. I think there is somewhat of a design flaw in these things. Or maybe the new caps I had were bored too large or something.

Sam

 

Just a note for next time ford dealers are expensive. I don't buy anything from them unless it is the last and only option. if you need anything with the motor call up ford get the part #'s and prices and check with your local International Truck dealer or find a local Diesel injector pump shop. I bought my Injector return line kit and o rings for $30 at my local Injector pump shop in New Hartford . Shops like that would never stay in business if it wasn't for old diesel tractors.

 

Thanks for the tip. But I called everywhere and everyone told me that I needed to go to the dealer. Normally I avoid dealer parts too.

 

I went to an injector service company to check out an '89 F250 I'm going to buy. He told me to buy it, but it had the original injectors (159K). Bought a set of new for $28.50 each and installed them. He sold the set of return caps for $30.

 

In most cases when you start messing with the caps on one injector you disturb the others and they start leaking, so the best advice is to change all of the orings, dont cahnge the caps unless they have a groove in them where the oring rode. This will sve you haveing to go to this injector then another leaks and so on.