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Hello all, I'm having problems with my 1990 7.3 f 250 that I just bought to learn wrenching on and am hopeful you all can help point me in the right direction.
I have leaks/air intrusion at the injectors and fuel filter. I changed the o ring on the fuel filter and bought two sets of fuel injector return lines.
The o ring on the fuel filter fixed that issue but both sets of the return kits failed me. One was the wrong size hose. Now this second one is leaking like crazy. It seems the issue is the o rings that I put on the injectors aren't making a seal.
My question:
If it leaks now, it won't "set" and be fine later, right? If that's the case, where can I buy stuff that will actually fit this truck and not leak? I'm not too happy with myself for buying the parts I did and hope to not make the same mistake again.
Also: if I have to buy o rings separately, what sizes and type would I be getting? I'm willing to spend a tad more if it makes all this **** just work.
If there's answers to this somewhere on the forum, I apologise for not finding them. Getting a tad irritated with myself here and appreciate your help!
Buy a couple bags of "O" Rings. They are around $7 a bag plus shipping.
Saw a link some posted on Amazon. $6 a bag and free shipping, now
can`t find it. https://www.mcmaster.com/9464K24/
When you install the injector caps.
Grease up the top of the Injector threads and O Ring.
Roll the first ring over the threads into the first groove of the injector.
Roll the second ring over the threads and the first ring onto the second groove.
Assemble the 4 caps and hoses together and install them as a set.
Be sure to grease the inside of the caps so they slide over the rings and snap in place.
Make sure there is no rough edges inside the caps from being cast. sometimes there
could be a sharp edge to cut the O Ring. Use an Exacto knife or Razor blade knife to smooth it.
The kits come in 2 sizes or styles. Think the 7.3 uses a 1/4" hose and 6.9 uses 3/16" what I
read either style will work on either engine. I might have my hose sizes wrong. 7.3 uses
the large size.
If down the road you move one and it starts to leak, do the whole side. Fixing the leaker,
you will move the next one, it will leak etc.... and you will be chasing the whole side.
I've always used STP to slick up the O rings ... but be sure you check inside those plastic caps for Burrs ... and yes several styles are used but all will work
You can buy it at any auto supply.
I read a thread, maybe on OB, where a guy used a Zycam lid to slide the O Rings over the
Injector. Checked the price on Zycam, forget about that for just LID.
Another guy used a short piece of clear plastic hose to fit over the threads of the injector.
Then slid the O Rings down the greased hose into place.
This was to keep from the possibility of nicking the O Ring.
Be sure that when you install the cap, to push on them until you head them click, it's a pretty faint click, and sometimes a real bugger to get them down that far, but if they don't they won't seal at all.
Mccarr or eBay has the orings, #111 make sure they're viton..
Keep all the caps you have left over even from the old set. Every now and then I have one that swells and won't seal anymore and I'll dig into my stash and I don't have to buy a whole nother kit. Most autoparts stores will have diesel rated fuel line for between the injectors. 3/16" for early style, 1/4" for late style.
X2 on keeping the caps for those just in case moments.
I have even dragged home some from PNP that looked good.
I used one that only had the one hose barb, to use when I
deleted the return line from the filter to the first injector below it.
As I mentioned above, disturb one cap and the next one will leak.
I cut the return hose so I had an inch or so, put a small bolt in it and
a clamp. Thought I was careful not to disturb the second one, but
guess not, it leaked also. So had to do the whole side of O Rings.
Good thing I have plenty on hand of the Viton Rings.
Replaced all the o-rings with Viton #111 O rings, lubed them up fine and they all fit well. I felt for burrs inside the black things and didn't feel any with my bare fingers. Tried the truck and it leaked worse than before.
I replaced the right side with the smaller kit parts and after a few trials, it seemed to seal alright. But then the left side started leaking. 🙃 At least I fixed the original problem!
The batteries are dying so I'm on pause until we can afford some new ones. Might go buy another kit of those black things and the hose just to make sure I have some on hand.
Something I noticed when trying the smaller hoses on the right side is that the two gold/brass nozzles that either end attached to was a pain the butt to get on. The hose is a tad smaller than I think the nozzle is intended for. Is this expected or am I going to have to use the bigger hose because of those nozzles?
Here's to hoping a few more rounds with the truck will get her going. Would be nice to drive the thing!
if you use the older style in place of the 1/4" new style then you need to add hose barbs to go from the 3/16 line to the 1/4 fittings ....forcing 3/16 line on a 1/4 inch fitting is just not a good idea.
if you use the older style in place of the 1/4" new style then you need to add hose barbs to go from the 3/16 line to the 1/4 fittings ....forcing 3/16 line on a 1/4 inch fitting is just not a good idea.
That's what I thought. Thanks for the clarification Wolf!
local auto parts stores and even places like Blowe's or Home Depot carry some Brass hose barbs....
You can even use plastic... like Nylon but keep them from touching any thing that gets hot.... I prefer Brass ... after all the Return cups are Plastic.
Got new batteries, got a new o ring kit. Got a new return line kit. Still leaking. At this point, Im giving up and calling a mechanic. I've changed the o-rings a handful of times along with the return lines. Each time it leaks. Maybe I'm just not meant to wrench!
I have been thinking about your problems with the return lines. Did you measure and cut the new lines between the injectors the same length as the old lines? Thats the only thing I can think of that would cause leaks. If the new return lines are too long or too short they could cause the caps to be tilted under strain , this might be causing your leaks. I measure my new ones by the old ones. ! other thing I do is roll the orings in grease , get it inside and on the outside. I hope this helps with your problem.
I did measure and cut them as close to the old lengths as I could without much success. Since I bought extra hose, I then tried cutting them shorter and longer, still same issue.
Called a mechanic friend, going to have him walk me through what I'm doing wrong and try to get new injectors and glow plugs while I'm taking it all out anyways
Last time I replaced the hose and "O" Rings, I bought rubber hose,
and you know how it will not totally straighten out from being in a
roll.
Cut the hose to the 4" pieces, the hose will maintain a slight curve.
Instill the first one to curve up, next down, next up etc... the Barbs
will not be in a line, but when installed with the new "O" Rings, it
does not leak.
Trying to keep the Barbs in a straight line, will put a bind on the Caps.
The Braided Cloth covered hose does not keep a curve to it.
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