Rear Brakes Locking Up In The Wet

[asdf205 0]

First time driving my current 205 in the wet tonight. I found that when braking normally/slightly harder (no emergency braking or anything like that) my rear brakes seemed to just lock up almost instantly. It mainly happend as i was slowing for a stop but it happend before some corners too which wasn't pleasant. Car is a 1.6 gti with the drums. Im thinking that it might be that my front brakes arent great so im putting more pressure on the pedal then i normally would be.

 

Also do the s16 disks and calipers bolt straight onto the hubs (not the rear) as im planning on using these? Is there anyway of running the abs from the s16?

[swordfish210 20]

Could be a seized compensator, however i do remember when i had a 1.6 beam on my car the rears would lock up without too much provoking.

[gowmonster 2]

do you get compensator on drum beams? i know the 106's only have compensator on disc beams.

[Ludi 2 2 Cars]

I had the same problem on my 205,changed the cylinders and everything was back to normal.

[Daxed 7]

Yes you do get a compensator on the std 1.6 GTI. The brake system is split front / rear, with a single pipe running the length of the car to the rear brakes. This pipe is then split via a T above and in front of the beam to supply each rear drum. The one and only compensator is close to the head of this run, mounted at a precise angle, low down in the nearside of the engine bay.

 

A fully working good condition system provides excellent braking, in all conditions, both front and rear and is nicely balanced.

 

Something is wrong with yours. This is not merely a function of having rear drums. It also appears dangerous and should be given immediate attention before driving the car again.

 

It seems to be a problem of bias.

 

If you have no technical ability with regard to the brake system, take the car to your usual MOT centre and get them to perform a brake test on the rollers. This should highlight deficient front brakes, causing the rears to lock, or deficient rear brakes possibly caused by insufficient compensation.

 

IMHO, as new, 1.6 standard front callipers with quality pads are the best solution for a road car, their inherent lightweight and cooling characteristics are excellent. They are however subject to wear and if not in A1 condition serious performance degradation is possible.

[welshpug 1,645]

sounds quite likely that the fronts need attention, I'd agree with Daxed and his approach.

 

Drums tend to be pretty problem free and consistent, whereas the 1.6 front callipers when tired can be poor, however when working they're very good.

 

S16 brake callipers+discs will not fit straight onto a 1.6 due to the larger offset of the hub, you'd need base model hubs with their lower offset and the same driveshaft spline pattern, or a pair of 1.9 hubs and 1.9 driveshafts.

 

 

If Swordfish's 1.4 with a 1.6 beam without any other mods, he would have had zero brake compensating, so I'm not surprised the rears locked up

 

(base models have the diagonal split braking system and compensator's integrated into the wheel cylinders)

 

 

To run the 306's abs you'd need to do some new solid brake lines, fit the 306 rear trailing arms complete, fit the front hubs, and find ABS 205 driveshafts, the wiring is pretty much self contained needing a few warning light and switched lives, as well as a few permanent lives.

[asdf205 0]

Thanks. Im upgrading to 1.9 driveshafts anyway so ill get some of the hubs too. I think i will replace the front brakes and see if that helps before trying anything else. The abs is also something i will look into in the future.

[swordfish210 20]

If Swordfish's 1.4 with a 1.6 beam without any other mods, he would have had zero brake compensating, so I'm not surprised the rears locked up

 

(base models have the diagonal split braking system and compensator's integrated into the wheel cylinders)

 

Yeah it was pretty interesting at first but i soon learned how to use it to my advantage. I was actually a lot quicker around combe with that beam than i was with the 1.9 disc beam as it was so easy to set the car up going in to a corner.

[yeti-dj 7]

Im also voting to sort out the fronts first, even just a clean up of the calipers and sliders to make sure that everthing is moving as it should may well help.

 

As for the ABS i wouldnt bother, its alot of work for not much return and will just give you more problems if it doesnt work correctly.

 

I also had problems with my 1.6 lockin the rears and sorted this by fitted a 1.9 rear beam and discs. haha

[welshpug 1,645]

ABS wont give you any issues when it doesn't work, it just doesn't work.

[Jamal 2]

To run the 306's abs you'd need to do some new solid brake lines, fit the 306 rear trailing arms complete, fit the front hubs, and find ABS 205 driveshafts, the wiring is pretty much self contained needing a few warning light and switched lives, as well as a few permanent lives.

 

 

The 205's 90 cog ABS driveshafts can be used for the 306's ABS? 306's using 29 cog.

[davidc 0]

I also had problems with my 1.6 lockin the rears and sorted this by fitted a 1.9 rear beam and discs. haha

 

Did you fit the 1.9 rear beam with the compensator or not ?

 

The reason I ask is that we're putting our 205 1.9 GTi together & theres no compensator there....should I get one & fit it or just use a bias valve....car will be used for rallys, track days, hill climbs, sprints, etc.