Engine/Transmission (1994 - 1998) Replace my lift pump??

[GAmes]

Here's my indecision. Awhile ago someone posted that the average life of a 12 valve lift pump was about 200k miles. So I bought one, threw it under my back seat and have been carying it around for the last 150k and haven't used it. Now that I am over 346k miles I'm wondering if I ought to replace it as preventitive maint or just keep hammering on the old one till it quits. It doesn't look like that hard a job, but with Murphy's law it will fail when I have a 12,000 lb trailer hooked up on a 7 % uphill grade in searing heat or a raging snowstorm. Just looking for an informed opinion.



Thanks

 

[SEmerson]

I have had 2 lift pumps fail. Both gave alot of warning with low fuel pressure. So if you have a guage you should be fine.

 

[CumminsAholic]

If you plan on keeping the truck and you have a spare 20 min, I'd replace it and throw the old one behind the seat for a spare... just because. But that's me and a lot of times I should listen to the "if it's not broken, don't fix it" rule. We've had a few give up on us over the years, a couple broken springs and the cam lever broke off the plunger on one... some lasted 350k+ and others under 150k.

Corey

 

[bmoeller]

Given the miles, I would go ahead replace it. If it were to go bad, it could possibly put fuel in the oil. The mechanical pumps will generally last a very long time. Very reliable units.



Replaced mine last year, I think was. It was making a loud ticking noise. One of the springs in the pump was tired, causing the rod on the pump to chatter against the camshaft lobe.



If you do a search on my username, I do have the install instructions written up.

 

[GAmes]

Thanks. I was leaning toward replacing and keeping the old one as a spare, just needed a push.



Gary

 

[BigPapa]

CumminsAholic,



He's got a 12V. Unless you have done 6 or 8 of them, have everything you need on hand, truck on a lift, and someone there handing you everything you need you will not do it in 20 minutes.



Gary, make sure to have about 2' of 1/2" fuel hose on hand. That's what took me so long, hunting for 1/2" fuel hose. I would do the stud trick, too. Read here:



https://www.turbodieselregister.com/...ad.php?t=129209



Scott

 

[GAmes]

I give. What do you need the fuel hose for? I know about using a longer bolt for reinstallation.

 

[HEMI®Dart]

CumminsAholic,



Unless you have done 6 or 8 of them, have everything you need on hand, truck on a lift, and someone there handing you everything you need you will not do it in 20 minutes.



Scott

My thoughts exactly. Plan on 2 hours minimum.

 

[Joe G.]

I MIGHT be able to r & r it in 20 minutes. I took it off so many times when I was trying to find what was wrong with my fuel pressure that I was thinking of installing a zipper on it.

 

[CumminsAholic]

BigPapa, I know he has a 12 valve, so do I they're just not in my sig. Why do you need a lift? I do mine from the top of the motor. I know for sure I can do it in under a half hour from shutting the truck off to having it running again. (Yes, I have all the right tools) If you go from the underside then it's a different story, but still isn't too bad if you don't have to keep getting out from the truck to get the right tools. Some people can do it from the top, some can't, it's a tight fit but can be done. But I shouldn't have said 20 min for a first timer, it'll take longer than that, sorry for the confusion.

Corey

 

[bmoeller]

CumminsAholic,



I would do the stud trick, too.

The biggest thing, make sure the cam lobe is on the low side. Won't have to fight the spring in the pump near as bad while starting the bolts.

 

[BigPapa]

I give. What do you need the fuel hose for? I know about using a longer bolt for reinstallation.

Sorry, I don't know why the link didn't work. Let's try again:



https://www.turbodieselregister.com/...ad.php?t=129209



Scott

 

[BigPapa]

Still won't work. Try this one:



https://www.turbodieselregister.com/forums/showthread.php?t=135865



There is a link in there to the original thread I was trying to link.



Scott

 

[GAmes]

I had no trouble in reinstalling the 90 dgree hose, but am now thinking I may want to replace it before I bolt it back together. 8 1/2 years and 346 k is a lot of time on a rubber fuel hose. Stud size by the way needs to be at least 5cm (50mm) long. No way I could have done this job while on the road, but now that I have done it and put in studs I think I could. Instructions for finding the low cam position in the manual suck. #1 piston TDC, then rotate the engine 180 to 270 degrees. I assumed they meant in direction of rotation, so went backwards with the alternator nut 1 1/3 rotation. Was that correct? Since I have to order the hose I can change it.

 

[BigPapa]

Gary,



Glad you got it done. You must have bought one of the older style pumps before they changed them 'cause the new pump is shorter and will not work with the 90*hose. My 1 3/4"-2" guess on the studs was pretty close. 50mm is just shy of 2".



As far as finding the cam lobe position I turned the motor over with the balancer bolts while my wife stuck her finger in the hole and told me when it was at the lowest point. What a woman?!



Scott

 

[bmoeller]

I got lucky. Didn't have to turn mine at all.