jamesStag Posted November 30, 2015 Report Share Posted November 30, 2015 Hello wise forum friends.. I have a fluid leak on my TR6 calipers so its obviously re-build time. I'm lucky enough to have a car hoist and good workshop, so will doing this myself. I've seen the various posts about quality issues with a few of the brake spares components (mainly master cylinders, seal kits, etc) So my main question is who would people recommend I source good rebuild kits from please? I've searched the forum, and also reviewed the buckeye triumphs brake caliper site. http://www.buckeyetriumphs.org/technical/Brakes/Front/Front.htm Mine is a '69 car, so I expect would have the early (poor) rubber dust caps on and 16P imperial calipers (to be confirmed as perhaps they are not the original calipers now!). From buckeye it seems the only change to upgrade to the later better dust caps that clip to both the caliper and the piston is to renew the pistons with the wider dust seal groove type. Can anyone please confirm if that is correct? Is the extra cost to upgrade to stainless steel pistons worth it? given mileage is only 2000 a year, and summer only driving (majority nice and dry) Any other tips or points noted from previous experience gratefully received. On a related note I have an annoying rattle traced to the brake servo. Its intermittent and only occurs at idle (if you crimp the vacuum line when it is happening then it stops.) The servo appears to work OK. I see there's a non return valve on the pipe connection to the servo. Is that the likely culprit or could it be internals of the servo? (at £35+ for replacement non return valve I'd like to know before committing!) I see from photo records that the PO rebuilt the servo himself back in 2008. so what the probability that an error by him could have created the vacuum related rattle? Cheers in advance, James. Quote Link to post Share on other sites
Guest ntc Posted November 30, 2015 Report Share Posted November 30, 2015 Not worth the effort,the new ones have no issues. Quote Link to post Share on other sites
Kevo_6 Posted November 30, 2015 Report Share Posted November 30, 2015 Hi James, as Neil states the new ones have no issues and I've had mine on for a couple of years now. I do about 3K miles a year in mainly dry weather. As for your servo I cant help much but I did improve mine by replacing the foam filter at the peddle end, mine was full of grease. I got the foam from an aquarium shop. Quote Link to post Share on other sites
Alec Pringle Posted November 30, 2015 Report Share Posted November 30, 2015 If you'd like your old calipers rebuilding, your local motor factor may deal with Brake Engineering - http://www.brake-eng.com/ Excellent engineers, I've utilised their products on an occasional basis for nearly 30 years, and my local factor reckons they're still as good and reliable as ever. Cheers Alec Quote Link to post Share on other sites
stuart Posted November 30, 2015 Report Share Posted November 30, 2015 TR Shop new ones are good, fit and forget and a good price. Stuart. Quote Link to post Share on other sites
jamesStag Posted November 30, 2015 Author Report Share Posted November 30, 2015 (edited) All, Thanks for the replies so far. I hear you are all recommending either buying new or sending the calipers away for professional rebuild. Is that because the rebuild kits generally available from the spares folks are either not that good, or its unlikely that a 'home engineer' would be possible to do a satisfactory rebuild in a workshop? (Noted that NTC says just not worth the effort to strip down units) Thanks kevo for your comment on the servo rattle point. Is this something that others have heard of before? Is the non-return valve the only real likely culprit? thanks and cheers, James. Edited November 30, 2015 by jamesStag Quote Link to post Share on other sites
Alec Pringle Posted November 30, 2015 Report Share Posted November 30, 2015 (edited) Hi James, I'd be much happier using a rebuilding kit from the OE caliper manufacturer . . . . as opposed to a kit from AN Other repro parts producer. It's not that difficult to take a caliper apart, getting it back together isn't always so easy ! All too often, having dismantled a TR caliper the problem of damage to bore and/or piston, through corrosion or scratching. becomes evident. Which means a professional rebuild or replacement. Damaging a seal during reassembly is all too common, as is scratching either the bore or the piston during the disassembly and reassembly process. With potentially anything from one thousand to two thousand psi in a braking system, it doesn't need much of a scratch to create a leak. Testing the finished article, the rebuilt caliper, is not straightforward in the home workshop - realistically, you're going to be testing it on the car, and at speed . . . . if the rebuild proves to be less than 100% successful then the consequences could prove embarrassing . . . . A professionally rebuilt and tested OE caliper is maybe £60-70 exchange, a new repro caliper from whoever is of similar price. Meanwhile the components for a proper diy rebuild are likely to be £25-30 per caliper, or more . . . . . It's not a large saving in cost, £30-40 per caliper at most, and a wadge of time spent . . . . . always assuming that your insurers have no objection to diy caliper rebuilding ? Cheers Alec Edited November 30, 2015 by Alec Pringle Quote Link to post Share on other sites
ed_h Posted November 30, 2015 Report Share Posted November 30, 2015 Having just rebuilt my servo (http://bullfire.net/TR6/TR6-52/TR6-52.html), I can say that there should be nothing inside that can rattle. The non-return valve however, has a loose ball or shuttle inside that rattles when you shake it. That is probably the number one suspect for the source of the sound. It also unfortunately suggests that you may have a vacuum leak in the servo which is causing abnormal flow throught the valve. Ed Quote Link to post Share on other sites
jamesStag Posted November 30, 2015 Author Report Share Posted November 30, 2015 Hi Alec, Thanks for your further detailed reply. Yes I follow what you're saying, and I do understand the points you raise about tricky assembly and potential for damage, and testing issues. All wise points I can see. The time to open up, clean and rebuild the calipers I'm not worried about, in fact I enjoy it. Given your points I think first thing is to confirm where the fault is, disassemble and assess corrosion / condition. If there's any sign that the leak is from the seal in the two halves of the caliper (from PO work perhaps) or corrosion has taken hold then granted its new calipers and 'game over'. Otherwise if the bores are serviceable, un-marked then I'm tempted at new pistons and seal kits and go from there. We've done plenty of tricky things in our workshop over the years, so not too concerned about the reassembly. However if I've seriously underestimated then yes I can resort to new calipers as suggested. Hi Ed - thanks for your comment on the servo rattle, In which case I think I'll give the new non-return valve a go. I'll also check that the servo is not taking in air when static. Thanks and cheers, J,. Quote Link to post Share on other sites
Guest ntc Posted November 30, 2015 Report Share Posted November 30, 2015 (edited) For £100 don't even think about it renew they are brakes your and other lives depend on them ( think about it) as for the noise the valve will be shot and replacements are rubbish,drill it out and replace with in line from miniparts.You will also find the correct small seals are nla Rant over. Edited November 30, 2015 by ntc Quote Link to post Share on other sites
Alec Pringle Posted December 1, 2015 Report Share Posted December 1, 2015 Hi James, nothing wrong with that approach, you've weighed up the pros and cons. One additional point - check caliper bore, against the possibility of a previous reconditioner having honed the bore and fitted a slightly oversize piston from 'a n other' application. It does happen. Cheers Alec Quote Link to post Share on other sites
geoffd Posted December 1, 2015 Report Share Posted December 1, 2015 I have just bought and fitted a reproduction caliper from Moss. I had to file the casting slightly to get it to fit. The car does stop so it obviously works OK! Geoff Quote Link to post Share on other sites
Dave McDonald Posted December 1, 2015 Report Share Posted December 1, 2015 James Whilst the majority of responses here point you towards repro calipers, you seem keen to have a go at refurbishing them yourself. From my own experience I wouldn't be put off if that's what you want to do. I've done several sets from when I raced my TR6 in the TR Register Championship in the "Roadsports" Class, the Regulations for which stipulated that standard brakes had to be retained. I bought standard pistons from one of the usual suppliers, probably Moss but can't remember. I used new seals from Raceparts (UK) Ltd in Wallingford simply because they were of a higher quality than standard, or so they told me, and better able to withstand higher temperatures. I didn't fit the external dust shields because they would have probably burnt with the heat but they wouldn't have been too difficult to fit if I had wanted to. I was advised not to split the two halves of the calipers because the internal O ring between them was very difficult to source and in any case not subject to deterioration. Not doing this didn't cause me any problems in use. An invaluable aid to removing the existing pistons was a short air line connected to the brake pipe inlet connection from the compressor, preferably with a valve in it to allow slow controlled application of pressure. They blow out easily. My TR5 had the servo rattle. It was the relief vale or whatever it's called. It was the early type which I had trouble replacing, eventually getting one from Past Parts in Bury St Edmunds. Hope this helps. Good luck. Dave McD Quote Link to post Share on other sites
jamesStag Posted December 1, 2015 Author Report Share Posted December 1, 2015 All, Thanks for further replies. I've had the car up on the hoist today and investigated, so an update.... The caliper that is leaking is from the pistons, in fact both seem to be weeping. I noted that this failed caliper appeared to have been rebuilt before (later style rubber boots, the other serviceable one has the early style on.) Hmm! pulled the failed caliper apart, careful controlled use of compressed air popped out the pistons no trouble. The pistons looked to be replacements, a couple of minor blemishes in the chrome finish on the main sleeve likely cause of the leak. The collection of corrosion materials behind the rubber boots was quite extensive, yet they seemed to fit well. The caliper bores themselves were corroded up to the seal point, then with some corrosion discolouration further into the bore. I set about cleaning one bore, solvent & rag and used a little 1000+ grit emery for the worst areas. After 30 mins or so of work I was not happy that the finish would not damage a new piston. So I now have 2 new calipers on order from TR shop.!! Alec, Neil & Geoff - Advice and points taken on board... Dave - I took apart the servo non-return valve. Its like a baby rattle and looks to be source of the annoying noise, but actually does still work as a non-return valve. The 'usual suspects' don't stock the early bayonet type valve, so I'll contact Past Parts in the morning. Failing that I'll take Neil's idea and drill the guts out and fit a separate inline valve. Cheers all, James. Quote Link to post Share on other sites
Guest ntc Posted December 2, 2015 Report Share Posted December 2, 2015 James Good call,do not forget to use shims if needed. Quote Link to post Share on other sites
jamesStag Posted December 2, 2015 Author Report Share Posted December 2, 2015 Neil, OK I'm aware of topic to centralise calipers to the disc. On removal mine had no shims (but I didn't check centralisation as it was). Had a look at Rimmers & Moss, if I do need them neither of them have stock. Any ideas on possible suppliers? Or just get some shim stock of the appropriate thickness and make my own?! Cheers, J. Quote Link to post Share on other sites
Guest ntc Posted December 2, 2015 Report Share Posted December 2, 2015 (edited) James Wait till you get your parts and trial fit,if needed I may have some spare. Edit Cut these 29 http://www.rimmerbros.co.uk/Item--i-GRID200419 Edited December 2, 2015 by ntc Quote Link to post Share on other sites
oldtuckunder Posted December 2, 2015 Report Share Posted December 2, 2015 Neil, OK I'm aware of topic to centralise calipers to the disc. Ok I have also read about this, but can someone explain why? of course I can understand making an adjustment if the caliper is close to touching the the disc, but given how calipers work and auto adjust in effect, why would it make any difference exactly centering the caliper over the disc? I would have thought first press of the brake pedal and your done. But I'm interested to learn better. Or am I being thick and this is about getting them parallel, which is important. Alan Quote Link to post Share on other sites
Guest ntc Posted December 2, 2015 Report Share Posted December 2, 2015 The more central the piston makes contact the better and may the force be with you Quote Link to post Share on other sites
jamesStag Posted December 3, 2015 Author Report Share Posted December 3, 2015 Hi Neil, Thanks for shim link idea. On the reasoning for centralising, must admit I thought it was about adequate clearance of the caliper casting to the disc. Or perhaps even pad wear (but only minor effect) I don't follow your last sentence. It's a hydraulic system, the pressure excerted on either pad is purely a function of hydraulic pressure. If one piston is marginally further out than the other there would be no difference on the force from the pads to the disc. The brake effectiveness would not be reduced as I see it... Cheers, J. Quote Link to post Share on other sites
Guest ntc Posted December 3, 2015 Report Share Posted December 3, 2015 J Uneven pad ware will tell you all Quote Link to post Share on other sites
jamesStag Posted December 3, 2015 Author Report Share Posted December 3, 2015 Hi Neil, I agree that if there is uneven pad wear on a car that does indeed say something is wrong. Most likely a sticky piston or pad. I don't see how a caliper that's not quite centralised would cause that to happen. Anyway - fitted new calipers today. Seems I don't need shims anyway, they are fine. Actually looks like there's only +/- 3mm tolerance before the disc would foul the caliper casting. Pedal seems firm in workshop, its not driven yet. Dave - spoke to Past Parts. Yes they've got a good second hand non-return valve, bayonet style. so that's in the post to me. Thanks for the recommendation. Cheers, J. Quote Link to post Share on other sites
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