A rear wheel cylinder question !!

[h11poc]

Hi all.. What size do I need for the 1991 GTii rear wheel cynlinder. The one I took off was the "two bolt hole" 14mm one but I am confused as to whether this was right. The rear brakes were lousy.

[mark1gls]

If you have the 2 little valves underneath the master brake cylinder then you should have the 17mm rear brake wheel cylinders.
The 2 valves reduced the pressure so you need the bigger brake cylinders.

Both sizes, 14mm and 17mm have the same fixings.

https://www.eurocarparts.com/p/pagid-wh ... -134440148

[h11poc]

Thanks for that. I did have the two regulators under the master cylinder so bought two cylinders from your link. The big bonus was there is an offer on those cylinders so they were just over a tenner each instead of 16.

P

[mark1gls]

Good luck undoing the bolts which hold the cylinders in place, make sure you clean out all the dirt from inside the Allen key head and tap the Allen key into the bolt.
When fitting the new cylinder coat the bolt threads in copper grease as it will help next time you change the cylinders.

There is always an offer at Euro car parts online, so make sense to click and collect or delivery as it’s cheaper than just walking into the store…

[mark1gls]

If your brake fluid is more than 5 years old bleed new fluid through the system as it makes a world of difference.

[h11poc]

2 litres of castrol brake fluid dot 4 acquired two days ago

[h11poc]

ALl brakes bled and working now. Took three or for bleeds to get all air out and now pedal firm and car stopping.

[mark1gls]

That’s great news. It can take a bit of time to get the air out as the fluid has a long way to travel.