Can't make injector cap stop leaking!
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Joined: May 2015
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Can't make injector cap stop leaking!
Just picked up a 91 F250 last weekend. Truck shows 26,000 miles on the odometer. I'm not sure how many times it has rolled over.
Anyways the engine has a wobble while at idle, but clears up while driving, so I doing the standard air in fuel procedure.
I bought a injector install kit from a local diesel shop and installed all new hoses , o-rings, clamps, and caps. Now I have one cap that I can't get to stop leaking! I've pulled it off and inspected the o-rings, changed it with three other caps and all with the same results. Anybody have some insight on what to try next?
Oh the kit is made by Interstate-McBee, and usually their stuff is pretty good quality.
Anyways the engine has a wobble while at idle, but clears up while driving, so I doing the standard air in fuel procedure.
I bought a injector install kit from a local diesel shop and installed all new hoses , o-rings, clamps, and caps. Now I have one cap that I can't get to stop leaking! I've pulled it off and inspected the o-rings, changed it with three other caps and all with the same results. Anybody have some insight on what to try next?
Oh the kit is made by Interstate-McBee, and usually their stuff is pretty good quality.
Postmaster
Joined: Dec 2011
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Get yourself a pack of spare o-rings off amazon; you want Viton O-rings, size code 111. Should be $6 or so for a bag of 50.
If it leaks, replace it. even if it looks OK. These things are finicky.
My special technique is that I use lithium wheel bearing grease when assembling it; slather it liberally on the O-ring, top of the injector etc.
Put it together and give it a couple of hot-cold cycles to seat and see what happens.
It seems to work for me; The lithium grease(instead of vasoline) works much better and won't melt at high temps; I guess it provides an extra sealing layer or something? No clue. But it works.
If it leaks, replace it. even if it looks OK. These things are finicky.
My special technique is that I use lithium wheel bearing grease when assembling it; slather it liberally on the O-ring, top of the injector etc.
Put it together and give it a couple of hot-cold cycles to seat and see what happens.
It seems to work for me; The lithium grease(instead of vasoline) works much better and won't melt at high temps; I guess it provides an extra sealing layer or something? No clue. But it works.
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The o-rings are brand new with the kit. I'll try the grease and see what happens. I used oil before and I guess it didn't swell the o-rings.
The theory of putting oil/grease on the o-rings is the same as it is for an oil filter. It makes the rubber swell and seal. This is why you usually can't re-use o-rings.
The theory of putting oil/grease on the o-rings is the same as it is for an oil filter. It makes the rubber swell and seal. This is why you usually can't re-use o-rings.
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Joined: Feb 2015
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Get yourself a pack of spare o-rings off amazon; you want Viton O-rings, size code 111. Should be $6 or so for a bag of 50.
If it leaks, replace it. even if it looks OK. These things are finicky.
My special technique is that I use lithium wheel bearing grease when assembling it; slather it liberally on the O-ring, top of the injector etc.
Put it together and give it a couple of hot-cold cycles to seat and see what happens.
It seems to work for me; The lithium grease(instead of vasoline) works much better and won't melt at high temps; I guess it provides an extra sealing layer or something? No clue. But it works.
If it leaks, replace it. even if it looks OK. These things are finicky.
My special technique is that I use lithium wheel bearing grease when assembling it; slather it liberally on the O-ring, top of the injector etc.
Put it together and give it a couple of hot-cold cycles to seat and see what happens.
It seems to work for me; The lithium grease(instead of vasoline) works much better and won't melt at high temps; I guess it provides an extra sealing layer or something? No clue. But it works.
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Joined: Feb 2015
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Good luck with the brakes! mine nickle and dimed me until I replaced everything short of the hard lines. replaced both calipers (sticking) soft lines, wheel cylinders, and bypassed the rear ABS valve because it was sticking too! pesky old truck brakes haha
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Everything is good with the front and I can get fluid through the rear I just can't get any pressure out of the rear lines. I have pressure and clean fluid at the valve on the frame rail by the steering column.
As far as the cap goes-I used some wheel bearing grease and of course it's still leaking. I guess maybe I stretched the o-rings too far when installing them or something. Looks like I'll be picking some new ones up.
As far as the cap goes-I used some wheel bearing grease and of course it's still leaking. I guess maybe I stretched the o-rings too far when installing them or something. Looks like I'll be picking some new ones up.
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Senior User
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if you were close i'd gie you some. i ordered 50 viton o-rings from mcmaster carr for $13. I have tons of spares
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From: Western Mass
You might need to bypass the RABS valve to get the rears to work well. The RABS design on these trucks never really worked well from the factory and many owners bypass or otherwise disable the system. I believe if you take off the big nut on the unit there is a spring behind it that can be removed. Once the spring is out, it just fills up with brake fluid and the brakes will work better. (at least thats what I remember, I never had a problem bleeding mine out and just ignore the RABS light on the dash)
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You might need to bypass the RABS valve to get the rears to work well. The RABS design on these trucks never really worked well from the factory and many owners bypass or otherwise disable the system. I believe if you take off the big nut on the unit there is a spring behind it that can be removed. Once the spring is out, it just fills up with brake fluid and the brakes will work better. (at least thats what I remember, I never had a problem bleeding mine out and just ignore the RABS light on the dash)
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Thats where i was at with it. A new valve is $$ also. I pulled the spring out, it was still hanging up. Tried the bleeder and everything before I gave up and just bypassed it. now it brakes awesome.
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What did you use to bypass it? Just a piece of brake line and two female ends?