Run-on Pump

[robpol]

So annoyed, was all set to do the pump today...

One of the clip has been put on in such awkward position too....couldn't have made it any harder to get off if they tried...

 

why do you think there placed where they are,its to stop poor peeps like you and me from attempting the fix in the 1st place, ;)

 

i just used some adjustable pliars to muller them,MAKE SURE you have the correct size jubilee clips before you start the job or your be fubared :)

 

 

Cheers m8

[Bigjeeze]

I bought the special tool for remving the clips -

[gregers]

I bought the special tool for remving the clips -

[Bigjeeze]

I bought the special tool for remving the clips -

[robpol]

I bought the special tool for remving the clips -

[sotal]

I recently fixed my run-on pump, it wasn't running at all and the booster heater was cyling upto 360*C then cooling down to 60*C then going back up. I wasn't getting any faults though.

 

I did mine differently though and didn't need to drill any holes etc.

 

The thing was dead so I wasn't too worried about breaking it so I undid the screws on the front (not sure if you can do this without removing the pipes as you could twist it round - would have been quicker to) This then separates the motor from the pump.

 

I then used a screw driver to bend back the tabs and remove the bottom of the motor. The brushes were just touching (108k). I found some brushes lying around in the garage from a power tool and filed them down I ended up filing down to 5x5x8 to clear the casing. I soldered them in place then realised how hard it was going to be to replace.

 

So I took the other end off, I placed it over the jaws of a vice and used a small bar to drift the shaft through the bearing.

 

You could then assemble the bottom with the brushes in place etc before replacing all the innards and the bottom together. To replace I stood the black bit with the bearing in on a bolt the same width as the bearing then placed the motor in place so the shaft was lined up, the shaft was then visible from the bottom so I used the bar I drifted it out with to drift it back in.

 

All fixed, and has worked perfectly for the last few weeks.

 

Drifting through an unsupported bearing can damage the bearing but it's that small I doubt it would, and I didn't care at the time as it was dead anyway!

 

Also I think there may have been a cover over the end of the shaft in the bottom part (where I drifted it back in) but this would have fallen off when I drifted it out, I think I heard something fall but couldn't find it.

 

I was stupid enough to refit using the original clips. I found a small per of long nose mole grips were almost perfect to remove the original clips, I say almost perfect as opening the jaws wide enough to fit meant they didn't open enough, I then used a regular pair of molegrips to turn the end of the small mole grips to tighten then grip.

 

Hope this method helps someone (I make it sound easy but as I didn't know what I was doing I did make a few mistakes which I have missed out! I'm trying to now find another duff one cheap to refurb to replace this one with now I know how to do it!)

Edited November 7, 2010 by sotal

[George106]

Regarding new brushes assembly I have read on another forum quite interesting approach. They didn't drill any holes to keep them in place but put just one drop of water on each brush whilst kept in the place by round object inserted inside and put in the freezer to let it freeze. Then you have to be quick otherwise everything defrosts and you can start again.

 

George

[gregers]

Regarding new brushes assembly I have read on another forum quite interesting approach. They didn't drill any holes to keep them in place but put just one drop of water on each brush whilst kept in the place by round object inserted inside and put in the freezer to let it freeze. Then you have to be quick otherwise everything defrosts and you can start again.

 

George

 

thats a good idea but only if you have the time to wait for it,i on the other hand needed the car within the short space of time i had to carry out the fix,so i followed the intructions in the faqs(twice now:blink:)and will do again if needed.but getting it fixed on the cheap is what it is all about and well done to everyone who does it,coz it is a pain in the arse.

[BigDog]

I just did the job - many thanks to all for the previous posts. I took some pics and will try to attach them after reducing the file size to something manageable. You can hopefully see I drilled some 1.5mm holes in the plastic end to hold the brush springs back and allow re-assembly, rather than use the water+freezer method or stripping the rotor assembly out like previous posters have suggested. About the brushes: I believe it is important to use brushes from a 12V motor, rather than a 240V high speed motor like a angle grinder. The mix of carbon to other stuff makes the resistance lower for the low voltage motors. Carbon brushes are very soft. Do not clamp them hard in a vice or they will crumble. I used spare brushes for a Valeo heater motor and cut them to length using a hacksaw blade. I did not use abrasive paper for fear of introducing abrasive particles and instead clamped a barstard file in the vice, being careful to hold the brushes flat. Use a wire brush to clean the dust out of the file a few times.

 

Also note that the motor body sleeve should not be clamped too hard in a vice as there are brittle permanent magnets inside it.

 

I measured the old brush width and height at 4.7mm square using a Vernier caliper. The inner diameter of the body is 37.7mm and the commutator is 12.7mm so there is 12.5mm radius for each brush, but you do need clearance to prevent shorting to the steel sleeve body, including the little hooks on the ends of the brush springs.

 

I reckon the wear ridge at the bottom of the commutator was less than 0.5mm. I did not clean the commutator with anything abrasive - it looked OK and from experience of trouble with these things on larger motors I reckon there is a danger of introducing scratches and increasing wear of the new brushes.

 

There is an electrical noise filter consisting of 2 tiny chokes and a blue capacitor mounted on this assembly. The old brush braids were spot-welded to the ends of the choke windings so I cut off the old brushes leaving about 3mm of the old braid to solder the new brush braid to. I had worried that the new brush braid was much thicker but this didn't seem to be a problem, experimenting with the springs ability to overcome the extra stiffness, all seemed fine.

 

I used a good squirt of WD40 to clean all the crud out of both parts of the motor then shook it dry-ish.

 

I put a tiny dab of lithium grease in the phosphor bronze bearing prior to re-assembly.

 

It worked first time. I nearly did a burn-in test by running the pump with the impeller end in a bowl of water but decided not to bother. I know the brush profile did not match the commutator perfectly. One last point - when reducing the the size of the brushes it really helps to have a Vernier or dial caliper - not only can you measure the size accurately but you can check the sides are parallel by swinging the brush in the jaws to check which end is bigger and needs reducing a tad more. Now to find out how to link to pics - it seems I can't just attachand upload them so will check the FAQ on that point. More later.

 

Matt

[dlt1617]

My pump hasn't gone yet but I thought I'd have a look on Fleabay to see if anything suitable was listed and I came across these:

 

http://www.ebay.co.uk/itm/Replacing-5mm-x-5mm-x-12mm-DC-Electric-Motor-Carbon-Brush-4pcs-/290825259242?pt=LH_DefaultDomain_3&hash=item43b68948ea

 

I just wondered if anyone who had done the pump could confirm if the copper braid off it looks suitable?

 

Best wishes

 

Dave

[SilverBeast]

They will do, but you are better to get brushes where the braid exits from the side. Below is a picture of the original worn out brushes in situ

 

 

and here the worn brushes with the ones I sanded down (mine are similar to those you picked but started off much bigger)

 

 

The main thing you need to check is that the braid won't touch the outer metal casing when they are fitted.

[BigDog]

SilverBeast, you beat me to it with pics. Here are mine below. I drilled two 1.5mm holes in the corners of the moulding pocket where the splice between the choke and the brush braid wire gets tucked. These holes ended up emerging in the mould tool cavity markings (see one of the pics) and I used stiff steel wire to hold the brush springs back when re-fitting the end cap assembly.

 

I did discover some rust starting under the rubber seal at the base of the scuttle plate thing. I will sort that out when (if?) the weather dries up. Also I re-used the coolant hose spring clips. They are not too bad to handle if you have some small vise-grips and I would be nervous tightening jubilee clips onto plastic i.e. not too tight to crack it but not too loose to leak; maybe I worry too much though.

 

Matt

 

http://i131.photobucket.com/albums/p301/mattlumb/P1010268_zps79cb1e2d.jpghttp://i131.photobucket.com/albums/p301/mattlumb/P1010271_zps1715da61.jpghttp://i131.photobucket.com/albums/p301/mattlumb/P1010275_zps4d75b4c9.jpghttp://i131.photobucket.com/albums/p301/mattlumb/P1010276_zps6cb99a6f.jpghttp://i131.photobucket.com/albums/p301/mattlumb/P1010281_zps0a861460.jpghttp://i131.photobucket.com/albums/p301/mattlumb/P1010265_zpsae2b2588.jpg

[xavier]

Did mine today (and yesterday!). Top learning points I took away were :

 

Get the proper tool to get the hose clips off (I got a draper one for £35 from amazon, they have cheaper but reviews said they tend to break).

 

To remove the electrical connector from the pump, slip a stubby flat blade screwdriver up the back of the plug to release it - don't spend 45 minutes pulling, inserting scredrivers, mole grips etc to get the thing off, get the clip open and it slides off easlily

 

if your hoses are like mine (not been moved in 106K) they'll be a pain to remove. Can't offer any help here, however would suggest eye protection to stop you spraying anti-freeze in your eyes (yes, I did, and yes, I had released the pressure first).

 

I got brushes from amazon, look for 1/5" by 1/5". £2 delivered for 4. Will report back if they fail in an untimely fashion.