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Power Steering Pump DIY

220K views 63 replies 31 participants last post by  TomoTW 
#1 · (Edited)
My daughter owns a 2001 Cooper with 47k miles. A couple of weeks ago she told me how the steering had "locked", luckily not in a dangerous position and she was able to stop safely. When she restarted the car it performed normally again but was obviously concerned. After she told me I looked on the internet and this site came up and has been a great help. Yes, the pump made a noise when the wheel was turned so I knew a new one was needed. Having seen the prices quoted from Mini or even independant garages I looked into the DIY option. Firstly I bought the Haynes manual to see what was involved and soon realised it was a viable option (the whole job is only 8 sentences). This is my experience of the job. First was to find a pump. I tried a company that reconditioned pumps on exchange but had no luck with them as they never had any any available and not very helpful! Luckily I found GSF who supplied a brand new original equipment pump for not much more than a recon, and it arrived next day. I found the job can be done fairly easily with the front wheels on wheel ramps, a little cramped but safe. Further to the Haynes I would add:- unless you empty the reservoir first be ready for fluid to go everywhere when the hose is disconnected, it runs around the pump then onto the subframe. Also note a new clip is needed as the old one is not reusable. The 2 electrical cables are secured to the pump body with tieclips which will have to be cut and new ones needed for the new pump. Also the tieclip holders will need transfering. With the old pump removed thoroughly clean the location and leave the plugs in the new pump until ready to connect pipe and hose, the smallest bit of dirt or grit could destroy it or shorten its life. The fluid I used was Comma CHF 11S (green) which is recommended for Minis, pour it in slowly then take the weight off the front wheels and turn the steering from lock to lock without the engine running, check the level and then lock to lock with the engine running and the car moving. This should bleed the system easily. The whole job cost under £300.00 including Haynes and fluid and took me about 4 hours. I am not a mechanic but used common sense and followed the book. Lastly please help your pump by not holding the steering wheel on full lock against the stop, only turning the steering wheel when the car is moving (parking etc) and never turn the steering wheel when a front wheel is hard against a kerb. Hope this has been of some help and thanks for the forum.
 
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#4 ·
More specifics on changing the Power Steering Pump

OK, so I just finished replacing the Power Steering Pump on my '03 MCS. I could not find many specifics on the job, so I am going to try to add some of those here. This was my procedure as I remember it.

1. I used my Mighty Vac to suck as much of the fluid from the reservoir. I couldn't get it all, but at least 90%.

2. Disconnected the low pressure hose from the reservoir (the one toward the front) and again used the Mighty Vac to suck the fluid from the hose.

3. Remove the cooling fan for the pump. (2 13mm nuts) To complete the removal you'll have to disconnect the wire connector, easy release by pushing the lever on the side.

4. Remove the 13mm nut holding the front of the pump down, roughly in between the two that held the fan in place.

5. Remove the two 13mm bolts from the backside of the pump. This is pretty much blind, unless you have some sort of mirror or freakishly small head. You have to come from the backside of the cross memeber and they are at the bottom of the steering rack. You should be able to feel them. The exhaust down pipe made one of them a little tough to get at, but not bad.

6. I used my Dremmel to slot out the hole at the front that the 13mm nut came off. The bracket for the pump was stuck under the engine mount, so I could not lift it out.

7. The high pressure hose is a solid metal tubing that is bolted to the pump with a 13mm bolt. It is a little tight, but you can get it unbolted. There is an o-ring type of press fit for this connection, which you will have to overcome to get it released. Carefully pry it apart. Some fluid will drain out.

8. Now it is just a matter of sliding and twisting the pump around until you can get the pump out. Having the low pressure hose attached made this slightly more difficult, but also made it cleaner. It is also fairly difficult to get the low pressure hose off of the pump while it is on the car.

9. Lastly you can now release the two electrical connections and the pump will be free after you cut the nylon zip ties holding the wires to the bracket.

10. The pump is connected to a bracket which will not come with a new pump, and probably should be removed before sending in to rebuild. Four 10mm nuts and to T30 Torx will separate the pump from the bracket.

11. Now just reverse this process to install.

12. The fluid was available at my local NAPA. Sitting right on the endcap as I walked in the door. I didn't even have to ask for help. $22.50 with tax.

13. I filled the tank, cycled the steering back and forth (while still on jack stands) both with the ignition off and then on. Drove down the street weaving back and forth several times and then checked the fluid level.
 
#5 ·
I replaced my PSP over the weekend - the two sets of directions/explanations here were spot on... my only added advice would be to seriously consider slotting the bolt hole in the sub frame - it would definitely ease the removal and replacement for the next round... my process took a little longer than expected (4 hrs total) but I didn't break anything and no parts were left unaccounted for - thanks for the detailed write-ups!!
 
#7 ·
how many litres of power steering fluid does the cooper S take to fill up ?
It has been a while since I did this, but I am pretty sure it took just the one quart and I had a little left over.
 
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#17 ·
I've seen some threads re: how to "clean" the dust and then some on what's necessary to truly rebuild it... our facility manager has some good suggestions that I'll pursue. If it works as expected (hoped) I will definitely post up - the $500 price for the new pump almost ruined my day, especially when the problem will probably arise again...
 
#18 ·
I suggest you try cleaning out the dust from the motor as a first step. It has worked for me.

I have not read any suggestions that the problem with these pumps is associated with the mechanical components or the drive motor. I suspect the problem is being caused by the control module. The typical symptoms of a noisy pump could well be control module operating the pump at high speed and a continuously running pump could also be a faulty control module.

As the control module is right next to the motor it seems possible the highly conducting dust (copper and graphite) from the motor brushes and commutator would cause the control module to go faulty or not behave as designed to.


It would really good if someone could get bottom of why these pumps fails prematurely.

Good Luck
 
#19 · (Edited)
How to fix a power steering pump

The power steering pump in my wifes mini packed in, I couldn't believe the the price of a new item so I thought I could have a look inside.
I am a qualified electronics engineer with a motorcycle parts business.

So here in steps is how to dismantle it, this isn't ment for novices but mechanics or other engineers.

Remove the pump from the car
Remove the fitting brackets and fluid pump from the end of the motor.
Remove the screws holding the motor body together and seperate.
I had to drift out the shaft from the brushes section.

So why did you motor fail, well the motor is fitted with carbon brushes,
over time the carbon brushes wear, the carbon then flies about inside.
The motor is fitted with a computer system, (lots of chips) the carbon dust settles on the chips (which should be sealed with a laquer but arn't).
The carbon is a conductor so it totaly screws up the computer, as dust it is also a poor conductor so tends to disrupt the operation rather than totaly destroying them.

all you have to do is wash the carbon off the chips with a little brake cleaner and allow to dry. I removed the brush assembly but to do this you have to cut the link coils between the computer at the rear of the motor with the brushes. When refitting these need to be resoldered onto the original positions, these are originaly spot welded.

Now that I know what the fault problem is, it may be possible to just spray the brake cleaner through one of the holes on the brush mounting plate, but you risk not removing all the carbon, too little fluid and you leave carbon, too much fluid and you risk drying out the end bearing.
If anyone would like some photo's of the job, let me know.
6 months on, the motor is faultless.
alan
 
#22 · (Edited)
How to fix a power steering pump

The photo's
The first shows the brush plate after I have refitted and soldered the 4 connections.
second is under the fluid pump, you have to remove the circlip and drift out this shaft.
So split the case first then remove the circlip and drift out the shaft, get ready to catch the armature assy and don't let it drop.
third shown the armature (oposite end from the circlip) after removing case

last shows the computer after cleaning, the carbon dust is very sticky and can't be blown or brushed off, you need some solvent but keep it away from the bush bearing in the centre
 

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#28 ·
The photo's
The first shows the brush plate after I have refitted and soldered the 4 connections.
second is under the fluid pump, you have to remove the circlip and drift out this shaft.
So split the case first then remove the circlip and drift out the shaft, get ready to catch the armature assy and don't let it drop.
third shown the armature (oposite end from the circlip) after removing case

last shows the computer after cleaning, the carbon dust is very sticky and can't be blown or brushed off, you need some solvent but keep it away from the bush bearing in the centre
ive seperated the pump and removed the circlip but cant seem to remove the armaratre???? any help?
 
#23 ·
Excellent, there are some photos on TotalMini (see link below) but I think yours is the first to detail how to clean and access the electronics/computer part of the pump in detail, which often seems to cause the problems. I will have a spare pump to rebuild in the next couple of weeks so this will be a useful reference. Thanks again for sharing. :)

ADVICE THREAD: Power Steering Pump Failures - totalMINI Forums
 
#24 ·
WISH i seen this post sooner :( only just replaced my power steering pump with a reconditioned pump from BAA Reman @ £200! If I had any tell tale signs that the pump was going to break I would have taken it out and cleaned up as best I could to save on buying a new one.

This is why this web site is so usefull !
 
#26 ·
stuff

Im about to use that bba-reman place but only because there is a leak on the PS pump. I hear a moaning noise when turning the wheel but its mainly because the fluid has been low. I would prefer to try and fix the pump from leaking if at all possible, anyboby have any ideas of where the fluid could be coming from? Havent totally pulled it out yet but should have it out this weekend.
 
#27 ·
this is the great thing about the web a simple search and all the answers. Alan thanks for the detailed instructions on disassembly and cleaning have already had the pump apart on my 03 cooper once found one of the main terminals had corroded and snapped had repaired that and cleaned the stator/rotor section of the motor, that area was full of carbon dust, but had not removed the brush plate and cleaned the control boards. have refitted to the car and the pump runs initially for a few miles but then stops or operates intermittently. I'm going to remove again strip and clean properly will post the results when the job is done.
 
#31 ·
thanks guys...i eventually got it removed by having to be a bit brutal with it....i also took it apart and cleaned the electonic bit...the pump is back on the car now and working fantasticlly, just waiting to drive it some more...i have taken lots of pictures and hope to write a full diy for anyone esle who decides to recon thier pump.

let it be known that even though pulsey advised that it is a professenals job, mechanically "minded" ppl could also easily pull this off.
 
#37 ·
this is great!!.. i couldve used this info a few hours ago lol... I being overly curious decided today to take apart the pump in my wifes car, from the pics its probably good i didnt have the right torx bit and could only get one side off.. when the cover flew off due to the magnetic force(which i had no idea was going to happen because i had no idea what can of worms i was opening) a huge cloud of dust erupted in my face. coughing and blind i ran out of the shop... ha ha.. when the dust settled, i could finally see what the hell mess i caused and wow.. its a magneto thing.. that cant be conducting electricity covered in dust. i dumped out probably 1/2 a cup of this asphixiating purple dust wiped the contacts banged it around to get more dust out, wiped more and put it back together. Bam!! the steering works, for now.. when it goes out again ill give it a proper clean like you have posted.. thanks for the info.. if you can tell me how to get this horrible taste out of my mouth form the dust let me know,,
Rob
 
#38 ·
Hi Guys,

This guide helped me a lot. So thank you! :smile:

I stripped my pump out yesterday. Cleaned everything I possible could and bleed the system. It's working now! I was having intermittent problems. Pump
would only work after letting the car sit for a few days. Would only work for about 30 min as well. Since last night no problems.

I want to know about the fan that cools the pump. Does it run off a temperature control or is run constantly and does it run at 12 volts?? Mine wasn't running at all last night so I'm a bit concerned about it. Does anyone know?
 
#39 ·
#41 ·
As others have said, I'm very glad I came across this thread!

The PSP hasn't failed completely on my 2005 cooper, but there have been other odd symptoms that might be explained by the build-up of carbon on the electronics.

Basically, every now and then the electrics in the car throw a bit of a fit, dashboard indicators flashing randomly (the car almost always cuts out shortly afterwards), headlights 'pulsating' and so on. A few days ago as I was parking the power steering cut out, quickly followed by the whole of the cars electronics. It wouldn't start again for a few minutes. I wondered whether it was a battery/alternator issue, but finding this thread it seems as though I'm probably a victim of the same problem, and hopefully a thorough clean of the PSP will at least cheer her up for a little while.

Has anyone else noticed similar electrical symptoms with a failing/dirty PSP or do I possibly have a secondary problem?!
 
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