Alfa Pages

Matthew Kirkcaldie · Posted: Mon Jun 02, 2003 1:00 am Post subject: Brake adventure

Well, some of you may recall that I have been asking about causes of shuddering and dragging in the rear of our 1985 series I, and that brake drag has been raised as an option by some of the wiser heads here. Our mechanics had looked at the brakes themselves, and the rear proportioning valve had been replaced from an unrelated incident, so I was thinking I was losing my mind because I still thought they were dragging.

On the weekend at the end of a 150km highway drive, I felt the car go sluggish and commented on the fact to my wife. We maintained 100km/h reasonably easily though. On reaching the turnoff for our destination we followed an old diesel 4WD at 80km/h and I noticed a growing scorched metal smell which I hoped was from the 4WD. Ten minutes later we reached a town and I had virtually no brakes. Got out and the rear wheels were radiating heat and emitting an almighty smell - plastic hubcaps would have melted or caught fire, thank god for alloys.

So I think I have an answer on the dragging brake issue! Interestingly it was both rear wheels, and the mechanic's initial guess is that damage / corrosion in the brake line may have acted as a valve, allowing the rear brakes to be engaged but preventing the fluid from returning easily.

So nice to know I'm sane, and I hope there ain't too much permanent damage. I guess I have done an amateur resurfacing of the drums though!

Cheers,

Matthew.

johne · Posted: Mon Jun 02, 2003 8:52 pm Post subject: binding brakes

Matthew,
One common cause of dragging brakes is internal failure of the flexible hoses, but since you have the problem on both rears it's either a remarkable coincidence or, as suggested, something in the pipe - perhaps the incident that necessitated changing the proportioning valve also damaged the pipework, or the new valve is faulty?
Just my two penn'orth.
_________________
Johne.
ex-33 P4 owner.

Ken McCarthy · Posted: Mon Jun 02, 2003 11:41 pm Post subject: Binding Brakes

Matthew / Johne

It could still be the flexible hose as there is only one at the rear of that model. It goes from the brake pressure regulator /distributor to the left hand side. There is a rigid pipe along the axle from there to the right hand side.

Regards
_________________
Ken McCarthy - 16V Sprint

Matthew Kirkcaldie · Posted: Tue Jun 03, 2003 1:12 am Post subject: The hose it is, I think

Gentlemen, as usual there is no substitute for the knowledge of true enthusiasts. As far as I can make out the mechanics in Forster are replacing the flexible hose due to suspected failure / corrosion / perishing - apparently a common problem on 80s European cars.

It's tough to know what is going on from 150km away but it sounds like they are on the right track. I am so looking forward to having the car back without the drag at the rear - the rental auto Corolla is pretty good, considering, but my heart sinks when I open the front door and I don't see the Green Hornet parked out there.

As far as the proportioning valve replacement causing damage, I had noticed the drag months before the valve was replaced. The valve was replaced because we did an engine transplant from a 1981 Sprint, and while the car was up on the hoist and the weight of the engine was gone, the pipes flexed and busted the valve. It looked fine when we left, but any application of the brakes caused fluid to gush out. Not good!

Actually, I have to say, I was dismayed at the lack of braking from the front discs when the rear drums were gone. They slowed the car somewhat but it wasn't anywhere near enough. I wonder if their function was also compromised, perhaps fluid had backed up and partially applied the discs as well, causing them to heat up and fade.

Anyway, I will report back on the repair and the results. Thanks again as usual.

Matthew Kirkcaldie · Posted: Thu Jun 05, 2003 2:00 am Post subject: Wind-up

Just thought I would let you know - expnsive job due to the fact that we had killed the brake shoes and cooked the bearings, but it all seems OK now. The hose wasn't the problem, but when they loosened the handbrake off, it went away, so it must have been partially engaged. Now the car travels more easily (duh) and I am flipping it right up to the redline just with my normal urban driving patterns!

Just a followup question: the brake pedal now seems to have more travel. Is there an easy DIY method to make them come on faster (i.e. can I adjust cable length easily?)

Gary UK · Posted: Thu Jun 05, 2003 6:41 pm Post subject:

Take it back to the garage and get them to adjust the handbrake properly (if you put the handbrake on a notch or two (without brakes coming on at the back) and the pedal firms then it has not been adjusted properly.