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R/R manual fuel pump

TommyD11730

TommyD11730

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Long and the short of it weep hole is peeing fuel. 84 GMC K2500 350. The @$%÷$!! Air injection pump just about blocks the view of the fuel pump. So I'm guessing that's got to come off to get to the pump. Oh, and it's been a while. I should be able to remove a bolt forward of the pump to stick something into the block to hold the rod up (if grease will not do it)....

Any other tips tricks? It's been a dogs age since I changed one.

Thanks!
 
Yes,there is a bolt in the front of the block that is in line with the fuel pump push rod you can remove ,it is one of the bolt holes formerly used to hold engine mounts on old 50's era cars & trucks..

What I've done is loosen the two fuel pump bolts,then crank the engine over by hand until the pump push rod is retracted all the way ,you can determine that by pushing in on the pump,it'll touch the block with little or no resistance when it is on the flat spot on the cam lobe that operates it..

Then take that bolt out, and put one that is longer (with enough threads to reach and touch the push rod) and GENTLY snug it up,just enough to keep the push rod from moving..then you can remove the pump and install the new one without having the hassle of the push rod wanting to drop out and "miss" touching the pump's rocker arm..

Some guys just take the pump off and the push rod out,and use thick grease on the push rod to help keep it "in" while installing the pump--I have done it both ways and like the bolt method better--but do NOT forget to remove that longer bolt,and re-install the original !..
 
Easy to remove the pump from under the vehicle on a lift.

Then just a 3/8" drive 9/16" shallow socket, a 5"x 3/8" extension, and a flex joint - then an 18" to 24" extension and your 3/8" ratchet.

I kept a 3/8" x NC bolt with the last 6 threads ground off into a pin shape to lock the fuel pump pushrod where I wanted it to stay..

When a customer's car came in, I didn't get to use the grease trick very much since the engines were all pretty hot and the grease always melted before I could stab the pump into the hole.

AND like previously mentioned --->:

DON'T FORGET TO TAKE THAT BOLT OUT
AGAIN BEFORE STARTING THE ENGINE!!!!​
 
Got to tell ya Joe, I crawled under my K2500.... between the engine "cradel" and air pump dosent look like this is going to be a "party".
Hate to tear up my rubbers on the inner fender but I'm wondering if it would be easier to access through the wheel well.
 
TommyD11730 said:
Got to tell ya Joe, I crawled under my K2500.... between the engine "cradel" and air pump dosent look like this is going to be a "party".
Hate to tear up my rubbers on the inner fender but I'm wondering if it would be easier to access through the wheel well.
Click to expand...

That's why I said to use that jointed extension trick. You don't really need to see the bolts - you know where they are - just push in for them.....with the socket and short extension. They're there!

It's not easy, fer true! - but I did it all the time. The Olds 350 in their full body cars was tougher and it worked on them too - that's how I got a job once by auditioningt on the boss's Vista Cruiser without tearing off a lot of peripheral stuff.

I actually use a 40" x 3/8" speed-handle to access those sort of things with the short socket and a 5" extension and then the ujoint on the end of my speed handle. The short socket is because a deep one will bind up on the pump housing and you can't get the first bolt out before you have to screw it back in and then get a short socket.

Believe me, it works. You can even change the plugs on a 1974 real Cobra 427 with that long speed handle when the manufacturer's instructions say to drop the headers and jack up the engine for access.

I always like to break the flat rate - it pays the same, and you can be off on another job to break that flag too so you get paid for two jobs at the same time.
 
Well that was fun. Pulled the air pump and diverter valve. They ain't going back on. :)

Will pull the air rails out of the manfolds next. Anyone make plugs for them?
 
On a happy note I fluid filmed the hell out of the truck.

Yeah, I forgot how much I loved working on all those 80s emission componets. :)
 
The flute pipes in the exhaust manifolds are a straight 1/4" pipe thread--I have used 1/4" npt pipe plugs with success to plug the ports,some manifolds had weird metric fittings--on those or some of the others with pipe threads, I cut the tubes flush with the flare fitting, and welded or brazed them closed..

Had to do this when I replaced a manifold and couldn't get one that didn't have the flute pipes..or I didn't need to pass an emission test,and the flute pipes had rusted away..
 
Thanks man. I have heard same as you, NPT and or metric.
Bet mines metric. :)
 
TommyD11730 said:
Thanks man. I have heard same as you, NPT and or metric.
Bet mines metric. :)
Click to expand...

I believe you'll find that there's no such thing as "Metric pipe threads" as they are the same pitch and taper, but the JIS versions (and therefor all of Indonesian and most Oriental countries) use the same standards - BUT - the so-called 'metric' pipe threads are not cut as deeply into the female side as the English/American pipe standards are.

Therefor, if you can get one full thread started, the US pipe threaded plugs should fit OK and vice-versa.
 
diesel4me said:
The flute pipes in the exhaust manifolds are a straight 1/4" pipe thread--I have used 1/4" npt pipe plugs with success to plug the ports,some manifolds had weird metric fittings--on those or some of the others with pipe threads, I cut the tubes flush with the flare fitting, and welded or brazed them closed..

Had to do this when I replaced a manifold and couldn't get one that didn't have the flute pipes..or I didn't need to pass an emission test,and the flute pipes had rusted away..
Click to expand...

Uh uh. There are no NPT threads cut in those holes.

They are threaded for either straight or inverted flares and the sidewalls and threads are parallel all the way from top to bottom of the threaded portion.

If one is insistent upon removing the AIR system - and I don't see why since it really is very good at eliminating hydrocarbons in the exhaust with or without a cat and all the rest of the emission controls --- then one might like to know that either a 5/16" or an 11/32" steel ball will fill the holes and you hold them in with the flare nut after you cut the tubing flare lip off and extract the AIR delivery tubes.

I - however - really don't like taking AIR systems off a vehicle as the cost to horsepower isn't even measurable - and the cleaning they do is very good.

Plus it's illegal at the Federal level, not just in your neighborhood - wherever that is.
 
Ok, I'll bite... how does pumping air into the exhaust reduce HC? Dilute it... maybe, but eliminate?

Like Fords EEC III to get them to pass emissions back in the 80s you..
Ran engine to operating temp..
Shut engine down..
Insert probe (4gas) into tail pipe
Start engine and test.
You had about a 3 minute window before HC and CO would fail

Yeah, 80s emissions, top notch stuff
:)
 
Even when Pulse Air in the BB Chevys in motorhomes had little more than AIR and Thermac, and when the pump went bad, the HCs climbed out of sight.

With it running correctly, the HCs were well below California limits.

But I don't need to substantiate my statements.
 
Ummmmmmm okay. I simply asked how it reduced the HC vs diluting it.

No reason to take offense.
 
TommyD11730 said:
Ummmmmmm okay. I simply asked how it reduced the HC vs diluting it.

No reason to take offense.
Click to expand...

Without going out to look it up, IIRC, it provides the oxygen necessary to allow any unburned hydrocarbons to be consumed in the exhaust. In some capacity and applications it's also tied into catalytic converter operation.

The solution is to stop running a carburetor lol.
 
dyeager535 said:
Without going out to look it up, IIRC, it provides the oxygen necessary to allow any unburned hydrocarbons to be consumed in the exhaust. In some capacity and applications it's also tied into catalytic converter operation.

The solution is to stop running a carburetor lol.
Click to expand...

You've got it. It's kinda like an afterburner to reignite the very burnable HCs with or without a cat for assistance.

It really works, and I have proof that requires a real keyboard, as this is being thumbed-out on my tablet and I hate this virtual typewriter.
 
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