Further Barke Problems

Hi Guys,
I had the dual circuit brake master cylinder replaced on my 1977 Spider 2000 Veloce a few weeks ago as the old one was sticking. However, on my first drive the brakes failed - pedal to the floor, only working when I pumped the pedal hard. I took it back to the garage, and the general concencus is that they must still have air in them. Two week later of bleeding, they are no better at all. Has anyone had the same problem, or does anyone have any suggestions at all? Am deperate now, especially as there appears to be a Sun in the sky!

I mean Brake Problems, rather than Barke Problems!

I thought I'd keep you all updated. It took three weeks for the brake system to be fully bled, and now they are completely air free. The brakes however are still not consistent, sometimes biting at the top of the pedal, other times near the bottom! The rear wheels have been getting VERY hot so we've gone for a replacement regulator valve and three new rear brake hoses. Has anyone else ever had a failed regulator valve? Were these the symptoms you had? If this does not work I think it'll be caliper replacements! If anyone has any other ideas please let me know! The weather seems perfect at the moment, so I want to get it fixed asap!!

Fitted a new Reg. valve on a HPE Beta, a while back now, as this was sticky, so hope you have sorted yours, for that fun in the sun.:

Well - new regulator valve is on along with a few new rear flexi hoses, and the brakes seem to be fine now - I think!. The only reservation I have is that the pedail still has a significant level of travel (1 inch) before the brakes bite. Also, they squeak quite a lot, and the rear wheels get really quite hot after a long run - hotter than the front wheels in fact. Has anyone noticed this on their spider, as if it is a common thing I'll stop worrying!!

Hi,
Is it maybe that the rear pads are sticking a bit in the calipers and not releasing fully after biting? I have not yet had the need to strip my rear brakes and take out the pads but I assume there is scope to put copper grease on the retaning pins and any surfaces where the pad backing meets the caliper body?

This should make them free to move back and not bind as your rear brakes should not really get hotter than the fronts and this indicates to me that yours are binding a bit. If they were sticking this might explain why you have free play before the brakes bite as the calipers take up the slack first.

If this has been done, then I can only think your caliper pistons are sticking or there is maybe a servo issue?

Cheers
Paul.

Hi Paul,
Thanks for your reply. Since I wrote my earlier post the brakes have got much worse again. The pedal was going all the way to the floor by the time I was putting the car away after a 70 mile drive. I'm taking the car back to the garage again on Tuesday. I'm very much hoping it is the calipers sticking. I think this would make a lot of sense actually as when I took the car out cold this morning the brake pedal had no slack travel, and the brakes came on instantly at the bearest press of the pedal - this is what I think they should be like all the time. But after my drive the pedal was near the floor before the brakes came on. Do you think this still fits with the caliper issue - the rear wheels are still hotter than the front. I really hope it is not a servo problem as it is a twin servo car - so expensive it may be!!
Thanks again for your help.

Phil

If the rear calipers are similar to the Lannies of that period, they can be a bit of a pain to sort! After lots of time spent trying to get the self adjusting mechanism to work correctly, I finally opted for a pair of replacements, which sorted the brakes once and for all.:

That sounds like the next port of call to me then! I think best to order a pair of rear calipers, as I don't want to clean and grease them to find that they get stuck again next time I take it out!!
Thanks for all your suggestions - if anyone can think of anything else I think I'll change that too.

I would take the pads out, clean the calipers etc and re-assemble with copper grease in all the right places first, before you go to the expense of a pair of calipers.

Its worth a try.

I guess you're right - try the cheaper fix first. As you say it might just work!!

Does it have pads and discs on the rear...? Anyway, if the pads are contacting with the disc this would explain the heat and it'll overheat the fluid leading to reduced braking and a soft pedal.

Sticky caliper is usually the result of a seized piston or sliders...strip down and clean

wrinx

Rear calipers are the thick end of £100 each exchange , but a seal kit to refurb your old ones is just over £10 . The Ate type calipers on my Berlina were real easy to rebuild (I guess they would be the same type on your spider).
"Whip" the pads out, clamp yer hose(s) disconnect pipe, and remove caliper from axle. Clamp caliper in vice by its mounting lugs, undo 4x nuts n bolts which hold the two halves together. Place a container underneath to catch the residual fluid and the small "O" seals in-between the two halves as they come appart (don't loose these small seals as some repair kits don't have them). Remove the old dust boots but keep the metal retaining rings to be refitted, then pull out the pistons, inside the bore you will see a slight lip of surface rust, this is most likely your problem, gently remove it with a fine wet n dry type paper. Clean up any remaining dirt and grime, then re-assemble in reverse order, not forgetting to lube the new seals with some silicone(rubber) grease as you go.
PS I've just rebuilt my front calipers today, same process only a little bigger
PPS If you have access to a workshop airline you can "pop" the pistons out before you strip the caliper body by applying pressure through the brake pipe "port", just remember to wear eye protection and to place a thick tyre lever or similar in the "slot" where the disc would normally be so as to give each piston an eaven chance of coming out before one or the other comes all the way out, thus loosing the seal and pressure acting upon the other.
Hope this helps a little or at least inspires someone else to try refurbing their own calipers, rather than having to put up with crap brakes or the expense of "off the shelf" refurbed units.

Inside the brake disk is the handbrake drum with small(ish) shoes. The handbrake mechanism can stick and create the rear brakes to get too hot.
You need 2-3 clicks free play in the handbrake lever before any actions takes place.
Erik

Thanks for all your suggestions. As we speak the calipers are being removed and looked at to see if they're the culprit. I did wonder about the handbrake, but it has two clicks of the ratchet before it comes on sufficiently to hold the car, so I think it's okay.
Will report back the findings in due course!

Phil

I think Erik may have meant 2 clicks before anything happens a the caliper. Two click to holding the car sound dead tight to me! Whatever you do, flush out all the old brake fluid and change it if this hasn't been done in living memory. It'll be so full of water by now (it's hygroscopic) that the insides of the calipers will suffer. Or consoder silicone brake fluid.

I think I'd better get that adjusted then. I've always thought it to be a bit tight, but I was told originally that it would be okay. As for the fluid, it was completely changed for silicone fluid when the new master cylinder went on a month or so ago. I know some people don't like the silicone fluid, but as you said it keeps the water at bay more successfully.
Will report back when I get any news!

I'm a huge fan of silicone fluid, but I confess to only having run a couple of cars with it. Just can't stand the thought of spilling that nast ethyglycy-stuff on new paint or rubber! Don't like it on my skin much either!
Talking rubber, these cars might be in the age bracket to suffer form the famous 'collapsed brake hose' syndrome. The flexible hoses swell internally when exposed to brake fluid over years untill they constrict and the brakes can't release - might fit the symptoms.

I've heard all about the nasty paint stripping properties of the silicone stuff!! I know someone with first hand experience - all over the bonnet of an E-Type - ouch.

The three rear flexible hoses were replaced when I had the regulator valve replaced - I'm a bit of a novice here, so am wondering if there are any more rubber hoses - I suppose there are probably two at the front as well, so maybe I get those done too!!

No, it's the non-silicone that's a paint stripper! The hoses may also be suspect as Wrenched pointed out. Hope your calipers are as Green Berlina said, and not like the ones on the Beta I had.:

The silicone fluid is supposed to be safer on paint, that's what I thought anyway. I haven't done a comparison on a nice visible wing-top yet though!
You do have flexis at the front, x2 I imagine, so it wouldn't do any harm at some point. You might even consider 'braided' (Aeroquip). Sorry, re-reading you did say you'd changed the rears.
It's a case of making sure the pistons and pads (and handbrake mechanism/shoes) are nice and free first. If things are running cool and it still develops a long pedal it could be signs of wheel bearing wear/half shaft endfloat, or a disc out-of-true. Disc out of true can generally be felt as a judder at the pedal.

Had some news. The handbrake is definitely okay and not dragging, so that's good. The rear calipers are about to come off for a good old inspect and clean, so I'm hoping that the problem is cured by doing that. The brakes are so vague, but I don't think the discs are out-of-true - although if they keep getting hot they may well be soon! I have had warped brake discs on my everyday car and it was quite noticable.

Out of interest exactly how good are the brakes when they are in "proper" condition. I was expecting them to be as good as a non-abs "modern" car - am I expecting too much of them??? Although I definitely know they should have a consistent pedal feel.

Sorry about the silicone/normal brake fluid confusion!