molten Posted February 19, 2011 Share Posted February 19, 2011 HelloJust received new kunifer brake lines for my spit and installed.Is there supposed to be some kind of thread seal used on the unions?Also, where the new unions fit into new rear slaves, the fitting feels a little loose. Could the female thread on the slave be a metric fit, hence the 'loose' feel?May be due to machineed thread on slave being a tad large. If this is the case, could anything be used to obtain better fit?Thanks for any advice.Cheers Link to comment Share on other sites More sharing options...
sparky_spit Posted February 19, 2011 Share Posted February 19, 2011 No, no thread seal is needed. The integity of the joint is maintained because tightening the union up squashes the flared end of the pipe onto the chamfered end of the union thus making a fluid proof seal. What is a good idea is to put copper grease on the threads so they do not seize together. You will be glad of this in 5 years time or so, when you may want to take it apart. Also put copper grease on bleed nipple threads for the same reason.Be aware that there have been both metric and imperial fittings used on Triumphs - imperial on early cars and metric on later ones. I'm not sure where the cut off is for cars that spanned both periods, but someone on here will know. Could this be your problem? I have to say I don't know whether one type will even fit to other albeit with a very slack fit, or whether they don't fit each other at all (in which case this is not your problem), but it's worth looking into if the former is the case. Link to comment Share on other sites More sharing options...
heraldcoupe Posted February 19, 2011 Share Posted February 19, 2011 The rear slave cylinders should be the same UNF thread on all Spitfires. From memory, the only metric fittings are those to the PDWA,Cheers,Bill. Link to comment Share on other sites More sharing options...
molten Posted February 19, 2011 Author Share Posted February 19, 2011 Thanks gents.Thought so, but noticed some king of compound on old pipes when removed - may have been rust :) mixed with old fluid??Regarding slaves/fit, test will be when system is under pressure. As this will be some way off, perhaps I will just have to wait and see.Thanks fella's Link to comment Share on other sites More sharing options...
Gt6s Posted February 19, 2011 Share Posted February 19, 2011 heraldcoupe wrote:The rear slave cylinders should be the same UNF thread on all Spitfires. From memory, the only metric fittings are those to the PDWA,Cheers,Bill.Late Gt6 front calipers also are metric thread. Link to comment Share on other sites More sharing options...
heraldcoupe Posted February 19, 2011 Share Posted February 19, 2011 Gt6s wrote:Late Gt6 front calipers also are metric thread.I know, the OP was asking about a Spitfire 1500,Cheers,Bill. Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 20, 2011 Share Posted February 20, 2011 loctite 542 is designed for sealing a variety of threaded and contact face sealing hydraulic solutions we used it on the production line for years without any troubles and after a lot of testingPete Link to comment Share on other sites More sharing options...
piman Posted February 20, 2011 Share Posted February 20, 2011 Hello Pete, there is no need whatsoever for sealant on car brake lines. If it doesn't seal easily with normal tightening of the unions something is wrong, in this instance it seems like a mismatch of threads or fitting length.Alec Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 21, 2011 Share Posted February 21, 2011 yes I know you have no need to use it but just saying it exists, it works as for the pipe sleeve nut fitting imperial will have 7/16"af nut hex and metric 10mm af hex there used to be proper identification on the 2 types but that has all but disappeared now , Pete Link to comment Share on other sites More sharing options...
Gt6s Posted February 21, 2011 Share Posted February 21, 2011 peterhlewis wrote: as for the pipe sleeve nut fitting imperial will have 7/16"af nut hex and metric 10mm af hex Not allways, I have 3/8 unf fittings with 10mm hex. Link to comment Share on other sites More sharing options...
TedTaylor Posted February 21, 2011 Share Posted February 21, 2011 The sealing action of the pipe is between the inside cone of the flare on the pipe and the cone inside the cylinder/caliper etc. where it fits. The pipe flaring tool makes a good accurate shape but the 'nipping up' of the nut shapes it to give the extra final shaping and seal.With deference to Pete and his experience, I personally would not want to put any fluid type sealant around this area in case even a small amount gets into the brake fluid and the contamination causes a problem. For nearly 50 years I have always done this job dry and never had any problems.The only time I have put any sealing anywhere on the system is when I have used my Mityvac to bleed brakes. When the bleed nipple is backed off after fitting the connecting pipe to do the bleeding, as you generate the vacuum you often get air drawn back past the threads into the inside end of the nipple which appears as bubbles of air in the pipe. This gives the impression that there is still air in the main system when there is not so to deal with it a use a narrow turn of PTFE tape around the nipple thread to seal it.Glad you are using cupro nickel pipe (i.e. Kunifer). Personally I dislike copper because it is so soft and easily damaged - and whenever I have had to undo a union on a copper pipe it is usually so jammed by the deformation of the copper because someone else has over tightened it that the pipe is stuck in the nut and destroyed. However I must admit that it is easier to form bends in copper but as I have a selection of about 5 mini pipe benders I don't find the extra hardness of cupro nickel a problem.Ted Link to comment Share on other sites More sharing options...
thebrookster Posted February 21, 2011 Share Posted February 21, 2011 Anyone know anything more regards the thread sizes etc??I have the problem with mine in that I have bought some braided hoses for the four corners of the spitfire. Only tried fitting them to the rear so far, and had to give up. The new hoses fit into the slave cylinder fine, however the join to the copper pipe is another matter!! The braided pipe simply will not meet up to the threads on the solid pipe union. It should be quite interesting to find out why this is so.(Ohh, this is an early MkIV Spitfire).Is not going to be problem, as I shall just replace the pipes instead, probably with Cupro-Nickel and will get the correct fittings when I do it.Cheers,Phil Link to comment Share on other sites More sharing options...
molten Posted February 21, 2011 Author Share Posted February 21, 2011 thebrookster wrote:Is not going to be problem, as I shall just replace the pipes instead, probably with Cupro-Nickel and will get the correct fittings when I do it.Cheers,PhilHi PhilI can recommed a supplier of kunifer pipes. I bought some new ready made in kinifer with all unions and flares for £37.00 delivered with very fast postage. Bought of a guy on ebay - well pleased so far. Link to comment Share on other sites More sharing options...
thebrookster Posted February 21, 2011 Share Posted February 21, 2011 Yes Please!!! Link to comment Share on other sites More sharing options...
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