Has anyone ever rebuilt the original Bosch fuel pump successfully after it failed?
I am using an identical looking pump at the moment which I bought new. Unfortunately, the pressure is not up to spec and while the bike goes OK, the tickover and low speed running is not great.
I stripped and cleaned out the original pump but am having difficulty putting it back together so that it will spin freely.
All the components are clean and corrosion free and the rotor and rollers all spin nicely until I try to tighten the outer plate which keeps them all together. Any more than fingertight and the rotor won't turn.
Has anyone any experience on this? Does it need petrol to lube the rotor?
I hate throwing the pump away if it can be resurrected and would put it back in the bike and keep the other as a back up.

I had the same problem with one I did, so I gently sanded the rollers until they spun. DON'T TO THIS. It pooched the tolerances, and now the pressure is hooped.

So no good advice, just a warning what NOT to do...

yep same with me john ......the only thing i can think of is to dissasemble the roller cell and polish up the parts , especially the top and bottom plates ...i have a suspicion that the contamination causes the rollers to slightly graze the running surfaces .

Yes it can be rebuilt, I cant remember quite where, but somewhere on this forum I have seen pic by pic disassembly of the pump so that it can be refurbed, I will look again and see if i can find it, so dont throw it out.....just yet anyway.

Guys, found it. look in tutorials for open fuel pump, by CF it shows how to take it apart.......

good luck.

Seen the excellent tutorial about how to take it apart.
Its how to put it back together is the problem!
I'm taking photos of each stage and hopefully will be able to show this if I can get it to work again.
Think there may be some mileage in your idea, Charlie.
The rollers and plates are clean and shiny, no corrosion, so it must be something small preventing it from spinning.
I noticed when stripping the pump that two of the four screws were not very tight.
I will have a go at polishing the plates. Any suggestions as what to use? T-Cut?
Do you think having petrol as a lubricant would make any difference?

hi john.....yes i think tcut is the right description ...in any case i would be going over it to acheive a uniform finish with the more aggresive compound ....but most important will be to clean it up after .....some or most finishing polishes have silicons etc ...probably best to wash off with petrol .
i think the ends of the rollers may also need polishing after looking at berts disassembly photos, i noticed some scoring on the ends.
good luck

I have seen ultrasonic cleaners on ebay circa the £30 mark. May be a worthwhile investment for the workshop as we all have injectors and filters to keep clean. I've seen the results of this type of cleansing and it's quite impressive..

Ian

Well, have it all back together again.
Cleaned all the components thoroughly but the critical thing in allowing it to spin seems to be how much you tighten the two longer screws which hold on the plate which keeps the pump parts together.
If you use something like a screwdriver with a normal handle the screws are over tight and the rotor won't spin. I had noticed when taking it apart that these two screws were not as tight as the other two.
Tomorrow I am going to swap the pumps over to test this one. If it doesn't work it will be hitting the bin. Because of the crimping around the top of the pump casing, you are only likely to get one shot at opening and closing it again.
Will keep you posted.

good luck john .....what did you do about peening /preventing the screws from undoing ...in the past i have used nail polish for locking loosish type things ...but in fuel, im not sure.

Drat! Never thought of that!
Wonder if should try to open it again.

Well, decided to strip it down again. Thought if it has any chance of working I need to make sure those screws are locked.
From what I can find out on line, thread locking fluid is resistant to petrol.
So I have put the screws back in, barely more than finger tight or the rotor won't turn, with locking fluid on the threads.
I removed the new pump ready to install the original one tomorrow. Want to give the fluid time to set before I immerse it in petrol.
Fingers crossed it works. I hope so, because despite the bad press the Bosch gets, it is a well made component and runs a lot quieter than the current one.
One thing to bear in mind is if you remove the pump from the rubber damper, make sure that when you put it back you place the inlet on the base of the pump so that its at the lowest point when back in the tank.
If you don't, it could mean that you may run out of fuel completely sooner after the warning light comes on. The difference is about an inch and that is a noticeable amount of fuel if you end up pushing it.
I had noticed that after changing the pump I was getting about 10 miles less on 'reserve' after the light came on.
Will post the results of tomorrow's test.
Also took a few photos during the strip so can do a bit of a tutorial if successful.

sounds like excellent work john .

i dont think that the bosch is a bad unit .......well with new rubber stuff anyhow .....just that all rollercells are prone to small particle contamination ....i guess we have hindsight and are aware now that rubber does breakdown or with the change in fuel additives best to keep an eye on it ...as it is almost always forgotten .

good luck

Well. That's another scrap pump!
Put it in and it was whirring but bike wouldn't start. Guess it isn't able to build up enough pressure. Could be losing pressure around the top of the casing where the crimping has to be prised open.
Put the new pump back in. Not perfect but at least it works.
Back to the drawing board.

Thanks guys, I was going to try a rebuid of a spare pump i had lying about. think I'll watch the F1 grand prix instead. If i obtain an ultrasonic cleanser I'll try it and report any news good or bad.

Keep smiling.

My fuel pump was stucked so i opened it by cutting the hose with a saw. I repaired the pump but the problem was how to fix a new hose. I used a pipe and i constructed a new iron hose on lathe machine.It didnt work for two reasons , first of all the hose must bemade from aluminum and not iron because it is getting rusty and the second problem was that you must used a press machine to seal the punp otherwise is leaking from the upper side of the hose. Afterthat i bought a used pump from e-bay. I believe you can adjust a new aftermarket pump with less cost.

So greecek100rt do I understand correctly? You had to give up and use the ebay one?
88

88KE wrote:So greecek100rt do I understand correctly? You had to give up and use the ebay one?
88

exactly