DJB3

Had to replace seals and pistons on my MY05 WRX 4 pot calipers. Once dismantled, it was clear that most of the pistons were corrode and I decided to use stainless steel pistons (full set with seals from Godspeed - excellent service). After rebuild and bleeding the brakes, slightly disappointed by the feel of the brakes. Pedal travel is excessive but does firm up on re-application. Thought that it might be air so bled again without seeing any air come out. Brakes felt no better. Decided that perhaps the brakes still needed bedding in. However on replacing NS front wheel noticed that disc felt a little loose. Thought that this would be sorted by tightening wheel nuts. No difference - whole wheel is wobbly in all directions. I'm presuming that the wheel bearing is worn (badly). This might also explain odd tyre wear and handling (steering felt oddly firm on turning to right around roundabout a few days ago).

Does all this make sense or have I done something stupid when re-assembling the calipers?

D.

360ste

iTrader: (1)

The wheel bearing could have something to do with it aswell, due to the wobbling of the disc pushing the pistons in further so you need to push the pistons out futher. Thus at the end of the first applicastion the pads are just touching the disc.

Another worthy addition is a brake master cylinder brace, will put a link up shortly. Made a good difference on my bug as it stops the bulkhead flexing when you press the brakes.

360ste

iTrader: (1)

http://www.ebay.co.uk/itm/TEGIWA-BRA...item2a148d1d62

This is one on flee bay but I have seen other sites selling them. Not sure if they are in either the group buy section or the parts for sale section on here also.

merlin24

iTrader: (1)

+1 for 'pad knock-off'

Mick

DJB3

New problem now - well, much worse version of previously mentioned problem.

On driving to work this morning, I turned right out of a junction. Steering became VERY heavy as if power steering not working at all and indeed for the rest of the journey, steering very heavy at slow speeds on either lock. Steering also reluctant to self-straighten on exiting corner/roundabout - had to wind to straight actively which feels very uncomfortable and frankly slightly scary.

When at work, had a quick look in engine (no tools or torch). Power steering fluid at MAX, can't tell if pulley loose (or missing) until later.

Can't help think that this is all related (to above issues). Please help me tie it all together.

D.

markjmd

iTrader: (11)

Jack front of car up, engage steering lock with wheels in straight-ahead position, then hold the wheel firmly with your hands at 6 and 12 o'clock first then at 3 and 9 o'clock, giving the wheel a good hard wobble each time. If there's more than a tiny amount of movement, your bearings are worn.

Options to fix are brand new OEM hub, low-mileage 2nd-hand hub, or if you can find someone local to do it, press-out and replace the bearings. I was lucky enough to find someone around here, he charged around £30 per side for the labour, and I sourced the bearings myself online for around £40 per hub (this was for a classic though).

JohnD

iTrader: (5)

Worn wheel bearings would not tighten the steering although a CV joint problem might! Also suspect, could be the bottom suspension arm ball joint.

JohnD

DJB3

Thanks. Will try to put on axle stands tonight and have a good look. Interestingly, when I became aware that the NS wheel was wobbling the play seemed to be at the outer CV joint although the boot looked intact which I presume would be the usual reason for failure.

D.

DJB3

Jacked up the car and checked everything. Still loads of free play in NS wheel (worse than ever). CV joint boot intact and other ball joints seem ok. Noticed that hub nut is further out than good side and tab was not in slot. Borrowed 32 mm socket - nut came off quite easily which clearly isn't right. Replaced it, tightening with long pipe over ratchet bar (supposedly around 160 lb ft but don't have torque wrench so best guess tightness for the moment). Free play now much better but still there.

Took it for a drive - steering still very abnormal. Quite difficult to describe. Heavy on full lock at parking speeds but only when moving. When stationary, power steering seems fine. Odd handling characteristics. Feels like geometry completely off.

Checked engine bay. Power steering fluid at MAX, pulley belt intact and tight. Smoking from around turbo/downpipe but I think that this was spilt brake fluid and became less obvious with time.

In summary, still think that wheel bearing is worn out but I don't think that this explains steering woes.

D.

DJB3

Advice please on whether power steering pump working?

Heavy steering on any lock. Heavy on parking, gets worse closer to lock. Ok on the move unless tight corner or roundabout and feels normal for slight adjustment to steering.

Sat in car today with engine running, turning steering wheel from lock to lock. Engine speed varies slightly (as it should). Steering heavier than normal. Switched off engine - did same again with keys in ignition. Steering so heavy that I could barely turn it.

I would have thought that the last finding might indicate that power steering working but something is physically preventing free movement. So I presume that this means a stiff or seized ball joint or steering component (rack or UJ)?

Car going to dealer on Saturday for diagnostics but might fix it myself depending on cost and DIY suitability.

D.

DJB3

Interesting findings at dealer.

Hub nut was loose - required another half turn. I knew that it wasn't right before but without torque wrench was too scared tighten too far free-hand. This supposedly fixed wheel free-play and certainly brakes now much better.

Steering - combination of problems. UJ corroded and improved by oiling. Power steering pump is failing though and will need to be replaced. Surprised that this should be needed on MY05 with 67000 on clock. New part cost eye-watering £600.

Have already sourced recon one for £230 but hoping to get lower.

Any ideas for recon pump?

D.

JohnD

iTrader: (5)

First time I've heard of the steering column UJ giving problems!
I guess the pump is "one of those things" Some fail, some go on forever!

JohnD

DJB3

JohnD

I've come across the corroded steering UJ issue a few times elsewhere on the net. It sits in the engine bay just beside the turbo so gets exposed to the elements and heat from the turbo.

D.

DJB3

Car went in for MOT today. Nearly failed because of unbalanced brakes. One of the fronts was 25% more powerful than the other side. I know that the off-side disc is slightly warped (it overheated when piston was seized) and the pads on this side were a bit pitted but wanted to wait until after caliper rebuild and test before replacing both.

Would warped disc or dodgy pads cause uneven brake force or do I need to take the calipers apart again?

ps power steering is now ok for about 1 week. I think that the power steering pump is ok after all.

JonMc

iTrader: (51)

How did they manage that, 4WD cars should be tested using an accelerometer and a short drive, putting them on the brake rollers is bad for the diffs

DonNedly

iTrader: (10)

Is it possible the abs is playing up?

carl heath

So if you take car for mot at a standard mot station how do they accuratley test breaks without an accelerometer on a 4wd ? Is it simmilar to the normal rollers ?

JonMc

iTrader: (51)

A standard MOT test station should have the right kit to test 4WD or advertise that they can't do it. This tests overall brake effectiveness but not brake balance; that is just the way it is.

JohnD

iTrader: (5)

Permanent 4wheel drive cars have to be tested on the road with the accelerometer (Tapley meter) on the passenger side floor. The only way to test for imbalance would be to check for pulling to one side.

JohnD

DJB3

Never used this MOT station before. Starting to lose some faith in dealer who had said recently that the car would need front drop links and ARB bushes all round to pass MOT. When I inspected these, I couldn't detect much wrong. They also said that power steering pump needed to be replaced when in fact I think that steering column UJ corrosion was the real problem. I decided to go to smaller scale, lower overheads garage to get MOT. This garage was recommended by tyre supplier that I have used for years. Have to be honest that I wasn't aware that 4wd cars require different MOT testing procedures to 2wd cars.

D.

DJB3

ps when I brake hard, the car does not pull to one side. Light braking causes slight pull to left ie when I lightly dab brakes with no hands on steering, it veers slightly to left.

carl heath

I had never thought of this either mate,ive seen the rollers in use but didnt pay any attention to our cars having to be tested another way ! We live and learn.