DIY rear wiper repair

[keithC70]

XC90 diy rear wiper repair

This morning I’ve managed to cure the faulty rear wiper on my XC90. It was working but was intermittent and would start and stop anywhere in the cycle.

Firstly prise off the plastic cover and undo the 13mm nut and lift off the wiper arm. Mine was tight so I used a small puller.

To remove the tailgate trim, prise out the light and remove the screw beneath it.

Next remove the handle trim. There are two indents in the upper face. I pressed the blade of a screwdriver in quite hard (straight in, not angled or prising) and pulled the upper edge of the handle at the same time with my fingers and it popped out undamaged. There are two screws beneath to remove.

The trim then pulls out.

There are then three 10mm bolts holding the wiper in place and a wiring connection to unplug. I let it hang from the wire and turned it on to see if it worked without the wiper arm and it performed exactly as before. It soon became hot to the touch so I guessed it was getting hot and being switched off by circuit protection.

On my V70s the problem has always been corrosion on the alloy tube tightening on the metal shaft. This is better built altogether with an o ring to seal the end of the shaft and there was no corrosion at all in the tube.

I decided to dismantle the motor. The screws have anti-tamper heads so I took them off with pliers and then cut slots with a hacksaw so I could replace easily with a screwdriver.

The gears were fine and with plenty of clean grease.

I prised the four metal tabs up from the brush end of the motor and pulled it apart and found the split ring commutator burned and pitted. The brushes were worn but with plenty of life left in them. So I conclude that it was sparking under load and then the heat was tripping the motor off. Some of the contacts may have been shorting because the splits were full.

I cleaned it with emery cloth and carefully ran the tip of a stanley knife down the splits to clean out any crud.

I then turned over the housing, popped off the cover and took the final screw off the circuit board. This lifts off and then you can see how the contacts to the brushes clip onto tabs on the board.

I then prised off the brush housing, held the brushes back against the springs and lowered onto the commutator – it’s quite fiddley! Then it’s all straightforward to re-assemble. I re-crimped the motor tangs in the vice, clipped the circuit board back down on the brush contacts, screw back in and clipped the cover back on.

I used plenty of grease on the shaft, screwed the cover plate back in place and refitted to the car and hey presto, one working rear wiper.

[martin j]

Great write up. Thanks for taking the time.

[pdrvolvo]

well done that man.

peter.

[murphysw10]

Hi, Just a question about your procedure for removing the rear wiper blade.

I recently swiped the rear wiper arm off my 2008 XC90 car when I drove under a barrier with the tail gate open and our christmas tree sticking out of the boot. Doh!

Anyway, I sourced a replacement arm on ebay but I am having big problems getting the old wiper arm off.

I removed the nut no problem but the arm will not budge. I am afraid to pull on the stub of the old arm too hard in case I wreck the motor.

Is it just a case of puling off the old arm or is there a trick to it?

Thanks

[R-P]

If it's anything like the V70, it's just corroded together (I think the arm is aluminum and it eats into the axle). Use plenty of IMAL or WD40 and use what is left of the arm to wiggle it loose. As there are teeth interlocking, also try to mimic the movement of the arm a few degrees hence and forth (if you understand what I mean...).

The 'teeth' are the grooves between the thread and the axle to the left in the below pic.

[murphysw10]

I tried some teflon spray last night as I couldn't find any WD 40. Will have another go with some wd40.

Will let you know how i get on.

Thanks

[murphysw10]

The teflon spray must have soaked in after night. It popped off with a bit of force when I tried last night. Looks like the motor is a bit damaged though. Wiper only goes half way and then stops. Uh well, at least it looks better.

[GrahamJW]

Just for the benefit of any others needing to do this - I've just changed this myself.

Some passing well-wisher decided to snap the rear wiper off, leaving just the arm stub that attaches to the motor spindle and its cover.

I think this was the original arm (with a blade I'd just replaced using a Volvo part for further annoyance) on a 56 reg. So was likely on there 7 years and fairly well bound.

One spray of WD40 and 5 minutes wait eased the 13mm nut.
A further couple of sprays onto the spindle at the front and rear of the fitting and a short wait allowed me to lever the arm stub off with two 1/8th turns of a large flat-bladed screwdriver placed underneath the fitting.

[steph16260]

After reading the post by KeithC70 my husband was inspired to have a go at fixing the rear wiper on our 05 xc90. It hasn't worked for about a year and we were quoted a ridiculous amount of money at the local volvo dealers, £200 plus just for the part with no labour. He took it all apart and found that it had totally seized up but with a bit of wd40 and a bit of brute force it is now working perfectly. Fingers crossed it keeps doing so.

[tad wise]

does the trim pull out if the tailgate is closed?