Engine/Transmission (1994 - 1998) Help - Replacing lift pump

[Bob Ellithorpe]

O. K. Guys I need your help !! I'm in the process of replacing my lift pump on my 94 dually. What I need to know is - what are the sizes of the two wrenches that are needed to disconnect the fitting oh the top of the lift pump. Nothing I have is a good fit and I don't want to put a sloppy fitting wrench on and end up rounding the flats off.

The pump has a fitting that comes with a new pump that has hex flats on it and the pipe fitting threads into that. If I put a wrench on the smaller fitting and they both turn I can end up twisting the pipe and I don't want to do that.

I've removed the starter and I'm trying to do it from below. Would it be easier to go at it from the top side. I really don't want to remove the master cyliner and fuel filter,but will if it's going to make things easier I will.

Waitng for some replys!!!

 

[HoleshotHolset]

I did mine from the bottom... . it's not much fun... . It's much easier if you can do it on a lift. The front axle will get out of your way if you can get it off the ground.



They're a bear to do on your back.



I honestly don't remember the sizes... but some of 'em were metric.



The inlet of the pump has a bubble flare on it... so that's probably metric.



Take a big 'ole knuckle buster and put the pump in the vise to remove the hose barb fitting and put the fitting on the new pump the same way.



Be careful to not damage the gasket in between the fuel heater and the block. I only changed the gasket between the pump and the heater... so far so good.



I also found that my 90° fuel hose that goes from the pump to the heater was too long with the new pump... . so I had to cut that short by an inch or so... .



Hope this helps out a little... .



Matt

 

[Bob Ellithorpe]

Lift pump

Matt,

I purchased the pump from Cummins and they said if I had any questions or problems to just give them a call. They also said they're not there to just sell parts,they believe in helping their customers.

I can just see getting that kind of help from D/C.

 

[illflem]

Bob, I've found it easier to go in from the top. Remove the fuel filter and the two nuts that hold the vacuum booster/master cylinder on. Even though it doesn't look like it the whole thing will swing towards the drivers side with only disconnecting the large vacuum line. I move mine every time I change the filter no problem. You will have plenty of room from the top after this. Don't remember the nut sizes but they are metric.

 

[Bob Ellithorpe]

Lift pump

One thing I learned while doing this - don't remove the pump mounting bolts before removing the pipe. Once you take the bolts out the spring in the pump is very hard to overcome and now at this point the bolts are to short to remount the pump. I went to a hardware store and purchased some longer same size metric bolts and drew the pump back in far enough to get one of the original bolts started and then remounted the pump so that I'll be able to remove the pipe whenever I find out what the wrench sizes are. Just remember to loosen the pipe first and to remove the mounting bolts last!!!

 

[illflem]

You can also have someone bar the engine over while you hold your finger on the cam that actuates the lift pump arm. When the cam lobe reaches it's furthest inward position the stock bolts aren't so hard to start. Your method sounds easier though, just as long as you don't have to go far (or walk) for longer bolts.

 

[Bob Ellithorpe]

Lift pump

Sometimes it helps to read the posts. Found a complete write up by CJ Johansson which includes all tools needed and step by step procedure for removal and installation of pump.

Thanks for all the other input.

 

[tropical trim]

Just changed mine about a month ago. I went from the top, took off the fuel filter and wheel well cover. By removing the wheel well cover I was able to inspect the cam shaft lobe that the lift pump rides on. Some one told me to check because a worn cam shaft lobe might be the culprit for low fuel pressure. Thank god mine was a lift pump failure. Hope this helps Kyle

 

[Cooker]

I know I am a little late now, but just a thought for anyone else reading.



If you remove the shock and upper shock tower, you have a fair amout of room to access from the side. If you removed the inner fender you would then have a ton of room.