M1009 lift pump replacement

[Barrman]

The mechanical lift pump on my M1009 started dripping two weeks ago. I parked it until a new Delphi unit showed up in the mail. Anybody that has done this repair knows to hate it. I have done it 2 times on M1009's in the past year. Practice did not make it any faster or easier.

Lots of threads about that though. This thread is about what has happened the next two fuel tanks and 600 miles of driving. The idle has gone up a noticeable amount. I haven't put my tach on it to see numbers, but it is for sure up a good bit. As in I have to push the brakes to stay still in gear instead of just putting my foot against the pedal while waiting for the light to change.

Much better low speed acceleration. Noticable improvement in keeping speed on hills while driving highway speeds too. MPG has stayed about the same. I think it will go up once we stop having our two weeks of "winter" and I don't have the thing idle a few minutes every morning and 20-30 mph head winds while going at higher speeds.

I think the mechanical pump had been going or bad for a while. I just didn't know it because the truck started fine and didn't leak fuel. This is just one more thing to think about when performance is down. Doing a psi test on the lift pump probably gets skipped by most of us. "Why check it since the truck starts fine and the filter stays full?"

 

[cucvrus]

I am all for the mechanical lift pump. It is easy to change and less then $25. Just changed one on the polar ice cap last week for a friend. Took me an hour and was glad when it was completed. COLD out for that job. But it had to be done. The wife was working or I would have ask her to do it. She changes them for $30US.

 

[doghead]

What was the old pump putting out for pressure?

 

[Barrman]

I didn't check. It was dripping from the weep hole, so I pulled it. The arm was extremely loose on its shaft. They all move some, but this one flops when you move the pump.

You have me curious about that now. It will be a month or so, but I have a 6.2 in my class with real easy access. When that is ready to turn over, I will throw this pump on just to see what volume and psi it puts out.

 

[donalloy1]

I am all for the mechanical lift pump. It is easy to change and less then $25. Just changed one on the polar ice cap last week for a friend. Took me an hour and was glad when it was completed. COLD out for that job. But it had to be done. The wife was working or I would have ask her to do it. She changes them for $30US.

Any tips for us that have never done this? Want to do mine and gather rod can be tricky to station keep while installing new one.

 

[AECS]

Put the rod in the freezer for about 30 min, while you are cleaning up the gasket surfaces and such. Dip the end in grease, and get it assembled up. Do not tighten it down 100% till you get the hard line on, this will give you some wiggle room to get that hard line on.

 

[Hasdrubal]

Put the rod in the freezer.

What is the purpose of this?

Its easier to get the rear most bolt started first as it has the worst access. Its the harder one to get threaded in, so do it first. Doing the front one first can lead you to spend hours trying to get the rear bolt aligned. Just thread it on a few turns..then install fuel fitting and tighten fitting, its almost impossible to do if you do the bolts up first. Then install the forward bolt, lastly tighten the rear bolt. On rear bolt I use a 1/4" ratchet with combination of just a long impact socket and then a short socket with a short extension.. The clearance is very tight, Helps to put some gasket sealer on gasket so it stays in place.

 

[cucvrus]

No freezer needed. Never heard of that one before. Yes it is a simple task. Be sure to remove the cover plate as I outlined before. And take the push rod and put some wheel bearing grease on that rod and shove it up it up into the hole in the block. Do not tighten any bolts until you have everything started. I use the gasket and Permatex the right stuff. About an hour job. Make sure and do it right. No short cuts.

 

[Skinny]

I don't understand why everyone has such trouble with the pushrod. You may need to bump the engine over if the assembly is difficult. I think the hardest part is getting the threaded hard line on. I agree, get it started first because it is near impossible if the pump is bolted down tight. Everything else is just an enormous amount of patience. Certainly not a ton of skill required but I remember it being quite a bugger to twist my arms up in there to get the mating surfaces cleaned up.

 

[AECS]

I like having the rod cold, it seems to give me some more time to get the pump up there before the rod falls, to each his own...

 

[Skinny]

What does freezing it do? I understand freezing components like bearings and other press fit stuff. I've never tried it with a fuel pushrod. Does it stick in the block because of the large temperature differential?

 

[cpf240]

I think the idea behind putting the rod in the freezer is that the grease put on it to hold it in place will stay firm longer, keeping the rod from moving.

 

[AECS]

I think the idea behind putting the rod in the freezer is that the grease put on it to hold it in place will stay firm longer, keeping the rod from moving.

This