alan c

Ok it might be corrosion of the pistons but cannot be corrosion of discs as i have put new discs on. if I understand what is being said about the master cylinder it could be a problem with part of that only, testing on rollers confirms it is front brakes only. Is it likely or possible for the master to fail in a way it affects front brakes only? As the calipers are now with AP I cannot do much more until they are back.

So far as I am aware it the standard as would have been supplied in early 90's when the car was built. I will have a look and see if it looks the same as a standard one on CC web site.

I did think about the master cylinder but when we tested the brakes on rollers the problem only occurs with the front brakes. I have therefore assumed, for now, that it cannot be the master cylinder on basis if that was the issue the vibration would be apparent on all wheels.

Hi I am fairly sure it's not the tyre and what are chances of both front tyres going out of shape? We tested the car on some MOT rollers at a friendly garage and you can see braking force varying on the gauges on both wheels, we tested together and individually and problem was the same. We cannot detect any play in suspension, any play was less than the other sevens we had available for comparison. Having said that if calipers come back and problem persists that has to be the only remaining thing not changed. I will update this thread when I make progress, AP will advise on timescale once they have inspected. Depends on what parts are required.

Hi Paul I should be able to borrow a disc run out gauge, fairly sure my employers makes/sells them so will check that. It is not something that gradually appeared so I don't think it's something that has worn. Car was fine then it was off road for a few months while I had the engine rebuilt and problem appeared as soon as I put it back on the road. There was no work done on brakes or suspension etc while it was off the road. If it is a bearing/hub/axle issue wouldn't I feel something at other times? I have the older style hub with felt seals

Not been aware of any variation in pedal travel

Hi, Apologies I thought I had posted a reply yesterday but if does not seem to have appeared. Disc to hub area was clean, issue first appeared with discs having been in situ for some time and I am sure it was all clean when we put the new discs on. Front and rear wheels are different widths so cannot try that but wheels are balanced no issue with vibration except when braking. Calipers now off and in way to AP for a refurb if that does not solve the problem I will replace all the suspension bushes but there is no play when you do the normal pushing and pulling of wheels and suspension.

Discs, pads and wheel bearings have all been changed and this has made no difference. Brake fluid was not that old and system has been bleed twice in process of changing all of the above. We have tested brakes at an MOT station on the rollers wheel by wheel front and rear and it only occurs with front wheels so cannot be master cylinder. I am taking the calipers off tonight and will send back to AP for a refurb and I was asking if anyone had experience of the AP refurb service. Alan

Update on this problem, still getting vibration under braking so over last few weeks with some help pads, discs and wheel bearings have been replaced and problem still exists. Managed to get the car on some MOT rollers and braking effort visibly varies but only on front brakes not the rears. So next step is remove the calipers and send them back to AP for a refurb - does anyone have any experience of their service?

Hi I have replied to PM messages and sent an email with some pictures but not clear if they have actually gone as I am getting an error message. I have extracted the stanchions from storage and condition is ok with some marks low down on passenger side where I used to have my tax disc holder. On drivers side there is an additional drilled and tapped hole for a mirror. Done by previous owner and I had forgotten about this as I removed that mirror ten years ago. So if they are of any use to anyone let me know, no cost, if not I will scrap them. Alan

Hi I believe they are in good condition I only changed them as I replaced my old screen with a newer anodized one and replaced the mounts at the same time. I can take some pictures and send them to you tomorrow if you send me an email address via PM. Alan

I have a pair of plain alloy ones if they are of any use.

My car has the VX 16V engine in it, originally this was running on Weber 45's and an electronic ignition but only 2D, i.e. no link to throttle position. I purchased a newer model ECU that could run a full 3D map. I got a basic map with that made life a little simpler it but after installation it did need mapping and you will need a new engine loom. (Loom I purchased was full loom capable of adding injectors later) Once mapped I got a little more power it was much more "driveable" and as an unintended benefit mpg was better. i did got to full injection later but first step was a big improvement. It was not an option when I did it but if you want the carb look you can convert the carb bodies to fuel injection. Hope the above helps.

Different engine but I did my upgrade from carbs to full injection in stages and most dramatic change was going to a full 3D ignition but still on carbs so have you thought about that to improve "drive ability"?

Thanks have managed some heavy braking sessions today and it's much better but not yet eliminated - will have try some more tomorrow. Never had this issue with the car before so don't know what I have done differently to the past. Combination of AP rear brake set up with useless hand brake caliper and under dash hand brake probably doesn't help. Then when it started I probably made it worse by braking gently. I will probably fit new discs anyway when we get home if I have not managed to eliminate the vibration as I have new discs already and I assume I could get the current ones skimmed to really clean them assuming they are not to worn. Thanks again for the advice

I get a fairly heavy vibration when braking, i have already changed the front brake pads as they were worn and when doing that I checked the discs and they run true. System was bled and pedal feels good when stationary. At same time there was some play in the rack so adjusted that as well. Vibration is only evident after a few braking events, ie once everything is warm. Car does stop but lots of vibration. Any suggestions on what else to look at, nothing else is obviously loose. The brakes are the AP 4 pots on vented discs as fitted to HPC's Alan

Thanks I had done that the problem was getting the remaining part out of the hub. There are only two flats on it for a spanner and you cannot fully rotate it using a spanner. Had a break and went back at it and got the second one off in the end, had to cut a slot in the top and combination of spanner, mole grips a flat screwdriver bit in 1/4 in drive socket set I got it out in the end. Was able to turn it 1/4 turn at a time using the above so took a bit time but all done. Suspect the ones I have removed have been on since the car was built so very old and no sign of grease on the threads of the old ones so even once moving they did not turn easily. I have put some copper grease on the threads so should come out easier next time but there must be an easier way to get them out than the method I used.

Apologies struggling to make posts upload and with threat ARB drop links. Spent all morning and only managed to remove one. Any suggestion on removing the link in the rear of the hub?

Try asking Northampton Motorsport, don't think they do MOT's but they use someone very close so they must be used to a variety of "interesting" cars.

Hi I would agree that metal sounds better than plastic but that view is not based on any specific experience. My engine has just been rebuilt at circa 50k and original water pump was fine so it was left. It is probably not essential but there is a special water pump "spanner" that will make like a lot easier. Think I got mine for a few pounds from Amazon/eBay. For cam belt I used a kit purchased from SBD but so far as I am aware it's run on standard GM to now with no issues. Alan

Musto Snug jacket covers wide range of temperatures for me, or just a soft shell top when warmer.

Also agree I have used the T1R's on my car for some time, its a VX so heavy and power was 190 but now very close to 220 and tyres are fine.

Depending on the make you can get them recalibrated but I suspect this is only worthwhile on more expensive units. I know that we do this for some of the brands within the group I work for as I have seen the process in action. All the units I saw were either very expensive or very large.

I used a small amount of silicone and some small dome headed bolts, think it was 6 or 8 per side. I wanted a solution that made it easy to remove/replace them in due course. Mine have been on the car a few years now and are just beginning to show some signs of wear. Make sure you seal any old rivet holes that are hidden behind the carbon or water etc will get in behind. Alan

Hi - glad to hear you have been able to repair it. I don't know if it will work but I am going to look hard at using the QED baffle in my car instead of the dreaded foam when my engine goes back together. Will post if it works.