Brakes: xc90 parking brake upgrade

[minstrelblue]

hi,
my 2009 xc90 parking brake is appalling and despite adjusting the threaded rod under the centre console it's still very poor so i've invested in the parking brake adjusters that replaces the 'h' bar in the rear drums, my question is should i slack off the centre console threaded bar beforehand and once ive fitted the new rear drum upgrade adjuster how do i set it all up, ie, do i adjust the rears until there,s some friction and then do the threaded notch bar under the console, so some detailed steps to guide me would be appreciated.
thanks [ hope this makes sense!]
neil

[S60D5-185]

Originally Posted by minstrelblue

hi,
my 2009 xc90 parking brake is appalling and despite adjusting the threaded rod under the centre console it's still very poor so i've invested in the parking brake adjusters that replaces the 'h' bar in the rear drums, my question is should i slack off the centre console threaded bar beforehand and once ive fitted the new rear drum upgrade adjuster how do i set it all up, ie, do i adjust the rears until there,s some friction and then do the threaded notch bar under the console, so some detailed steps to guide me would be appreciated.
thanks [ hope this makes sense!]
neil

It makes perfect sense and that's pretty much how I did mine.


Get slack into the system via centre adjuster, assemble rear brake shoes with new manual adjusters in place and then replace drum.


Adjust newly installed units via wheel bolt hole until very slight resistance is felt.



Depress parking brake by two notches and then go to centre adjuster.

This needs adjusting correctly and remember to reinstall the locking C clip once done.

I will try to find link to correct procedure for this and update this reply.

They are well worth fitting.

[S60D5-185]

Click on PDF link in Post 4



https://www.volvoforums.org.uk/showt...ake+adjustment

[Tannaton]

My suggestion....

Completely slacken the adjuster in the centre console, then fit the in-drum adjusters.

Then tighten the in-drum adjusters until you cannot turn the wheels at all or they are really difficult. Then slacken them 1/8th turn at a time until the first point at which you can turn the wheel until you feel no drag.

Then set the adjuster in the centre console as described.

The engineering principle is that the in-drum adjuster should maintain the shoe/drum clearance. The centre console adjuster maintains the resting slack in the cable.

Two further suggestions... :

- You must check the inside edge of the discs where the parking brake shoes contact for corrosion - if corroded then new discs needed or machining. You will not get a satisfactory parking brake if the discs are noticiably corroded, you cannot simply remove the corrosion with use as polished rust has a much lower friction coefficient than steel.

- Once set up - drive the car slowly and apply the handbrake to 3/4 effort - dive the car abound 150 feet like this to bed the shoes in. Do this 2 or 3 times, then repeat process about for the best parking brake possible. Maintain the brake by driving 150 feet with moderate parking brake applied say once a month.

[minstrelblue]

thanks for the info. will follow those steps and hope it solves it, mot due in may and it'll never pass as it is, so fingers crossed

[AidXC90]

Originally Posted by minstrelblue

thanks for the info. will follow those steps and hope it solves it, mot due in may and it'll never pass as it is, so fingers crossed

I've got an MOT coming up in a couple of weeks time and have the in-drum adjuster kit waiting to be fitted. So I was wondering, Minstrelblue, if your parking brake passed the MOT with the upgrade installed? Also, are the adjustable expanders installed with the toothed adjuster towards the top or the bottom of the expander?

Thanks in advance.

[Clan]

Originally Posted by minstrelblue

hi,
my 2009 xc90 parking brake is appalling and despite adjusting the threaded rod under the centre console it's still very poor so i've invested in the parking brake adjusters that replaces the 'h' bar in the rear drums, my question is should i slack off the centre console threaded bar beforehand and once ive fitted the new rear drum upgrade adjuster how do i set it all up, ie, do i adjust the rears until there,s some friction and then do the threaded notch bar under the console, so some detailed steps to guide me would be appreciated.
thanks [ hope this makes sense!]
neil

This non approved part does not make all good , IT masks the root cause of the problem , the parking brake is adequate if everything is working as it should do , a rusty drum and /or non volvo shoes makes for extremely low friction .

[Tannaton]

Originally Posted by AidXC90

I've got an MOT coming up in a couple of weeks time and have the in-drum adjuster kit waiting to be fitted. So I was wondering, Minstrelblue, if your parking brake passed the MOT with the upgrade installed? Also, are the adjustable expanders installed with the toothed adjuster towards the top or the bottom of the expander?

Thanks in advance.

I don't think it really matters whether the adjusters are pointing north or south but I always put them north as I think it makes for slightly easier adjustment and that's how they are fitted in every diagram I've seen etc.

Clan is of course quite right to point out that Volvo never fitted these parts to the XC90 and there is no recommendation from Volvo to retrofit them (unlike the later manual adjusting parking brake pedals) and if the system is in tip top condition you wouldn't need them. We also see a lot of people fitting them thinking it will sort an MOT issue, when the most common problem is corroded drum surfaces from lack of use and ineffective non-genuine shoes.

My own opinion though is that the parking brake system could have been designed better from an engineering perspective - the clearance between the shoes and the drum which will be a fraction of a millimeter shouldn't be controlled keeping a cable over 2 metres long under tension. When the cable ages, it will inevitable have more friction in it and this will make adjustment of the system more difficult and a sticking brake more likely. If a car at a dealer had these issues then the cables would likely be replaced and normal working order restored, but a more robust and reliable engineering solution would be to have a mechanism in the drum to control the shoe/drum clearance and the adjustment in the cable is merely to take the slack out of it.

In some ways it's strange that Volvo did not fit the adjusters to the XC90 as they are available as a genuine Volvo part and some other Volvo models did have them - the only meaningful difference on those cars was the parking brake was operated by a hand level not a foot pedal.

[AidXC90]

Thanks for the advice, Tannaton. I'll orient the adjusters as you suggest. I agree with you and Clan about this not being an orthodox solution but if it helps to get me through this MOT it'll have done it's job.
I did replace the front section of the cable a year ago and it passed MOT then, but it's slackened since then so I'll readjust it via the usual adjuster barrel in the centre console and I hope the shoe adjusters will be a belt and braces approach. If I have to replace the shoes, it's easy enough to do at a later date, but I don't want to fork out for new shoes in the next week or so.

[oragex]

Originally Posted by Clan

This non approved part does not make all good , IT masks the root cause of the problem , the parking brake is adequate if everything is working as it should do , a rusty drum and /or non volvo shoes makes for extremely low friction .

^^This. I would add worn cables. Mines are worn (still original ones) and very weak. I put the adjusters and it helped a little for a while - it also removed that 'free' roll before it engages. But these adjusters need to be adjusted manually periodically as the shoes wear off.

Ideally, the entire cables need replaced because they get damaged internally - can look at the place where the cable enters the drum from behind - the cable must have a small round seal here which cracks and fails after years, then water gets inside the cable and damages it.