Terrible Leak at Injection Pump

[supergas]

I replaced the injection pump on my '92 with a Bosch reman about 5000 miles ago, Worked great until today. There is a steady spray of diesel coming from the backside if the pump towards the front (drive end). It was dark when I noticed it so I just got it home. It got nearly 2 mpg on the way home. The bad news is I found out that the guy that sold me this pump no longer works at the shop and there is no records of purchase (must have back doored parts) so no warranty. I found this out when I contacted him looking for another pump for a friend. Also for the last month there has been a slight surge at idle is this related? I guess I will pull the pump tomarrow is there hope or is this a sign of more trouble inside the pump? What is back there to leak? Sorry for the long post just wanted to give anybody that can help all the info I can

 

[BushWakr - RIP]

If I remember right, there is a small plate (2 screws) with an O-Ring on the back side that will occasionally leak. If that's what it is, you got an easy fix once the pumps off. I don't think there is any way to repair without removing the pump.



Here's a link to my gallery with a pic of the pump. Look on the lower right side. You'll see an odd shaped plate, o-ring and screw illustrated.



https://www.turbodieselregister.com/user_gallery/displayimage.php?&photoid=2873&width=2



Bob.

 

[Dieselman359]

Bad News

Hey supergas, I hate to say it but I think that your going to have to take the pump off for some work. Last year at about this time my truck started to leak around where the pump bolts on to the back of the gear case. When the motor was idling you could see fuel running down the back of the gear case, and all over the motor. There is a seal on the shaft of the pump that was bad on mine, but I decided to have the pump went through while I had it off (150,000 miles) and, well, $600 later I got it back, put it on, and have been playin' with it ever since.

The bad thing about it is, if yours is leakin' where mine was, there is nothing to keep fuel from running into the gear case and mixing with your crankcase oil. I would advise you to pull your dipstick, smell it, and check the level. And if I have made any sense whatsoever to pull the pump off and get it repaired if it was doing what mine was. I noticed that you said the words "spray, and 2mpg" so you must be losing a lot of fuel. Mine wasn't acting that crazy, I mean it would run fine, but it just had a steady leak.



Hope this helps,

Chris

 

[BushWakr - RIP]

TTT,



Any news/update on how this came out or whatever??? I'm interested in the outcome...



Bob.

 

[supergas]

I have not had time to do anything yet things have been crazy around here

 

[DPKetchum]

Over a four year period I had four 91 to 93 model trucks come in with crankcase filled with diesel fuel and no obvious external fuel leaks. All of them were a pump seal. On one pump the injection shop called and said when they checked one of the pumps out they found NO leaks anywhere. I requested they go threw it anyhow and that repaired that one also. Dipsticks were maxed out when trucks were towed in.

 

[Evan A. Beck]

I see it all the time... The leak from the small plate/o-ring on the back of the pump is usually caused by one of two things... Small air bubbles in the fuel or a sticking (on) KSB solenoid. Pressure tends to build up in the pump and blow the o-ring out. Sometimes it will even bend the plate. So be sure to get a NEW plate and o-ring when you fix it. Also check the KSB operation.

 

[BushWakr - RIP]

^

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Ya, that's the thing I was talking about, thanks Evan





Bob.

 

[Evan A. Beck]

Anytime, Bob!

 

[supergas]

Thanks for all the info, I finally got the truckaround to the shop last night and am getting ready to pull the pump, would it be best to get a new KSB solenoid or is it wiring, Thanks Trey

 

[supergas]

All you guys were right, I pulled the pump this morning and one bolt was loose on the two bolt plate opposite to KSB and the green o-ring was missing about a third of it. Got an o-ring yesterday from a pump shop and he checked my spare cover all OK. Also got the thermal switch from Dodge just in case.

Well wish me luck I am heading back to the shop to reinstall the pump.



Thanks for all the ideas, Trey

 

[Evan A. Beck]

The KSB solenoid udually doesn't fail... Its typically the air thermatic swtich in the intake. That part seems be be prone to failing, and I have even seen a few of them bad right out of the box. Be sure to test it and make sure it turns off when the truck is warmed up.

 

[supergas]

I am going to check the KSB next I just got it bleed and running again and came in to relax.