I'm rebuilding my Injection Pump!

libbybapa · Post by **libbybapa** » Thu May 03, 2007 12:23 am

IF the bushings should be removed away from the center, then perhaps one could tap the bushings to take fine pitch all-thread. Then it would be a matter of a washer, tube and nut and they could be pulled out without the use of a press. I wonder if tapping them in is an option. Didn't Blue Oyster Cult sing a song "Don't Fear the Reamer"?

Andrew

Asymtave · Post by **Asymtave** » Thu May 03, 2007 6:55 am

Rwest1,

Thanks for the info and for the source for the cheap adjustable reamer.

In the pump rebuilding thread that Fatmobile mentions, there was a diesel tech by the name of Zips Diesel that said the old bushings had to pressed out in separate directions. In other words, outer one to the outside of the pump and the inner one to the inside of the pump.

He claimed this was good practice because there may be a "hump" or dumb bell shape to the bushing bore. Basically a high spot between the bushings. Have you had a problem with this? Maybe you're just pushing the extra aluminum out with the bushings and it's no problem.

One more thing - do you have a source for the new bushings? I currently have 2 pumps that need bushings. Last time I paid a shop to install and ream bushings, and while it was a good learning experience, I just as well could have bought a re-furb one from Jack with warranty.

Thanks again.

Asymtave · Post by **Asymtave** » Thu May 03, 2007 6:58 am

Libbybapa,

Tapping the bushings to pull them out is a good idea. The bushings don't have much wall thickness, though. A fine pitch thread might work maybe. I'll measure one when I tear my pump apart and let everyone know.

rwest1 · Post by **rwest1** » Thu May 03, 2007 12:31 pm

Iâ€˜ve read the thread about the choke point between the bushings, so I very carefully inspect under a strong loupe, and push very slowly until the first bushing hits the second bushing. So far I havenâ€™t ran into a pump with the restriction, and from a production / engineering standpoint I canâ€™t see a reason for it. The bushâ€™s seat flush with case on each end of hole, so you donâ€™t need an inside seating lip, and itâ€™s cheaper to make a thru-hole than run an end mill to depth in from each end. But since those crafty Germans designed it, I keep checking. Making a puller as discussed would not be a bad way to go, I just havenâ€™t needed to go there in the pumps Iâ€™ve seen. I buy the bushing from my local pump shop, if you know what you want, they will begrudgingly serve you! Have fun and like Mr. Bapa said "Don't Fear the Reamerâ€

Asymtave · Post by **Asymtave** » Thu May 03, 2007 1:08 pm

Excellent. Gracias.

Op-Ivy · Post by **Op-Ivy** » Fri May 04, 2007 11:20 pm

I have another question!

Are there any parts internally that one might consider replacing when rebuilding the pump. I have the seal kit, bushings, throttle shaft bushing and mainseal. Just looking to catch all the fish while I'm at the lake!

Thanks!

-Matt

Op-Ivy · Post by **Op-Ivy** » Sat May 05, 2007 12:14 am

And one more! The atmospheric bleed valve leaks diesel. The O-ring that keeps this from occuring is located here. How is the metal O-ring fitted in on top of the rubber O-ring? Is it pressed in or screwed in possibly? Or do you have to squeeze the O-ring behind it?

Its a very tight fit and I don't want to mash anything

Thanks!

Post by **Fatmobile** » Sat May 05, 2007 2:26 am

The LDA o-ring is internal.
You have to stop it from leaking into the LDA, not out of it.
It goes around the little pin inside the LDA,... the one that rides against the cone.

libbybapa · Post by **libbybapa** » Sat May 05, 2007 9:58 am

But, when that o-ring leaks the fuel flows into the space below the diaphragm which is open to atmosphere. When enough accumulates it starts coming out the atmospheric bleed. It's been a while since I changed that o-ring. I'll have to take a moment in the garage today and take a look. I'll get back to you on it.

Have you removed the feeler pin lever assembly?

If memory serves, then after that you have access to the o-ring retainer which is allen in the center and unscrews to allow the o-ring to come out.

Andrew

Op-Ivy · Post by **Op-Ivy** » Sat May 05, 2007 11:16 am

Hmm the center is round, so I don't think an allen head would work. But I was able to pry it out past the o-ring retainer. Putting it back in should be easier than getting it in though.

-Matt

libbybapa · Post by **libbybapa** » Sat May 05, 2007 12:20 pm

It looked round, but I figured it was just a blurry photo. I've only seen ones that were hex in the middle or that had a channel for a flathead screwdriver. It unscrews (or at least the others do). Bosh might have "advanced" their production with a press fit o-ring retainer (kinda like the push in ball bearings retaining the feeler lever shaft) and made it harder on the rebuilder to boot.

I'm not sure what to recommend. I'd be tempted to try some method to unscrew it (tap in a torx bit?) but you'd certainly run the risk of messing up the aneroid. Also, the feeler pin moves in and out and so you wouldn't want to make displaced metal that would rub on the pin.

On another note, Vincent, I measured a throttle shaft bushing and came up with 1.67 inches which converts to 42.4 mm.

That's almost double the largest one you mentioned.

Andrew

Vincent Waldon · Post by **Vincent Waldon** » Sat May 05, 2007 1:21 pm

Thanks for the measurement Andrew... I'll see what my local Bosch diesel dude makes of that.... looking at it from the side I certainly can see how it could be that tall... the one on my NA practice pump is quite a bit shorter so maybe thats where they started to read...

thanks again,

Vince

jetta90 · Post by **jetta90** » Sun May 06, 2007 8:42 pm

Vincent Waldon - regarding your question on length of throttle shaft bushing. They do vary in height/length - your pump number will tell the Bosch dealer a bunch.
If you have a " 182 " pump number in the serial numbers your pump uses the tall one. Have a check on these numbers.

Here's a query for all - once you have the pump opened up and ready to replace bushings, o-rings and mail seal - what else does one check for wear internally in the pump????? How about the 4 vanes (size of a chicklets gum) found on the vane pump on the low pressuer side of the pump?? It would be next to sinfull to neglect to replace something and button up the pump only to have to do it again later

libbybapa · Post by **libbybapa** » Sun May 06, 2007 9:43 pm

New vane pumps are available. I have been inclined to try to hand lap both sides of the vane pump. One would need to place the pump assembly with vanes in on a flat surface and use another flat on top with sandpaper. Extreme care would be needed to keep the surfaces parallel. Regardless, even with a new van pump you are doing nothing for the case which is two of the three sides of the vane pump.

Andrew

rwest1 · Post by **rwest1** » Sun May 06, 2007 10:39 pm

jetta90

Most of the IP refurb work done by the home mechanic is predicated upon having a pump that is working satisfactorily, other than it leaks, or has excessive main shaft wear. If youâ€™re having other pump related problems, or you want to change the fuel profile (increased performance, etc.) the work s/b left to the professionals, unless youâ€™re a real dedicated DIYâ€™er. Specialized pump testing and fuel profile measuring equipment is required if your doing more than a basic reseal and re-bushing of major wear points (Main shaft, control lever). Most older units have areas that exhibit wear (cam roller axles, advance drive pin, etc.) but what is acceptable is rather subjective and closely associated with the expected service life of your refurbed pump (you can change everything and have a new pump if you can afford it). I inspect and measure all worn areas, and use my best judgment as to what requires replacement (If anyone has specific wear parameters on internal parts, I would love to see them). Regarding your specific question about the vane pump, itâ€™s pretty easy to check/adjust (see threads on adjusting IP internal pressure) and verify its performance using a pressure gauge before any internal work is started (could be a problem if you have a massive leak affecting internal pressure). Regards