Steve1 Posted December 31, 2020 Report Share Posted December 31, 2020 Hello folks Can anyone recommend the best place to buy a replacement brake servo, or should I have my old one reconditioned? any good or bad experiences would be appreciated. Cheers Steve. Quote Link to post Share on other sites
barkerwilliams Posted December 31, 2020 Report Share Posted December 31, 2020 Steve, Depends where you live as the freight costs mount up and collection is a plus, but mine was from David Manners just off M5 in Birmingham and is absolutely fine. Alan Quote Link to post Share on other sites
aardvark Posted December 31, 2020 Report Share Posted December 31, 2020 I had mine refurbed by past parts about 5 years ago. More expensive than buying a new replacement but there were some dodgey new ones around at the time. It came back looking like new. cheers dave Quote Link to post Share on other sites
Waldi Posted December 28, 2023 Report Share Posted December 28, 2023 Past Parts reconditioned (and fitted a SS sleeve) on my clutch and master cylinders during my restoration. This summer, the clutch master cylinder started leaking, so I called PP, and decided to dismantle it myself, also because of shipping costs. Upon opening I found a longitudinal direction scratch and “black smear”, so I think the seal was attacked by the SBF (DOT5). It does not feel swollen, or soft, or hard. I contacted PP during the resto and they confirmed SBF was compatible with the seals, and so did Moss (who supplied the other seals in the systems). Now a question: I tried to remove the scratch (it is not deep) with a scotch pad but this does not remove it entirely. Can I use a spring-loaded hone stone (grit 240) with petroleum on the SS liner or will this make things worse? Okne the scratch is gone I will fit a new seal kit and hopes this solves it. Thanks, Waldi Quote Link to post Share on other sites
BlueTR3A-5EKT Posted December 28, 2023 Report Share Posted December 28, 2023 13 minutes ago, Waldi said: Past Parts reconditioned (and fitted a SS sleeve) on my clutch and master cylinders during my restoration. This summer, the clutch master cylinder started leaking, so I called PP, and decided to dismantle it myself, also because of shipping costs. Upon opening I found a longitudinal direction scratch and “black smear”, so I think the seal was attacked by the SBF (DOT5). It does not feel swollen, or soft, or hard. I contacted PP during the resto and they confirmed SBF was compatible with the seals, and so did Moss (who supplied the other seals in the systems). Now a question: I tried to remove the scratch (it is not deep) with a scotch pad but this does not remove it entirely. Can I use a spring-loaded hone stone (grit 240) with petroleum on the SS liner or will this make things worse? Okne the scratch is gone I will fit a new seal kit and hopes this solves it. Thanks, Waldi The item I think you suggest is sold as a brake cylinder honing tool I have had success using the same type of tool in a Lockheed TR2 brake/clutch master cylinder. https://www.diy.com/departments/small-brake-cylinder-hone-triple-leg-engine-honing-bore-flexi-glaze-buster/5056133335095_BQ.prd Quote Link to post Share on other sites
stuart Posted December 28, 2023 Report Share Posted December 28, 2023 Ive had some success with one of those honing tools, however it would depend on 1. How deep the "Scratch" is and 2.How compressed the new seal is in the bore i.e. would it take up more clearance as to whether it would be a work around. Stuart. Quote Link to post Share on other sites
Waldi Posted December 28, 2023 Report Share Posted December 28, 2023 Thanks Peter and Stuart, I have a honing tool like this and used it on aluminium cylinders several times, always with good results. The question is more if the SS sleeve can be honed like this too. I have nylon brushes too that I can put in my drill, but feel the stones will better remove the high spots. The scratch is likely from a tool-withdrawal during revision or so because it is not “straight”. Upon closer comparison I noticed the new seal is a bit stiffer, so maybe swelling due to incompatibility is the main issue. Waldi Quote Link to post Share on other sites
RogerH Posted December 28, 2023 Report Share Posted December 28, 2023 Hi Waldi, the SBF is very ineffective on doing anything to almost any rubber seal. It really is quite passive. All the seals sold for DOT4 will work well with DOT5 with no issues. Roger Quote Link to post Share on other sites
Casar66 Posted December 28, 2023 Report Share Posted December 28, 2023 42 minutes ago, RogerH said: Hi Waldi, the SBF is very ineffective on doing anything to almost any rubber seal. It really is quite passive. All the seals sold for DOT4 will work well with DOT5 with no issues. Roger You mean DOT5.1 or DOT5? We had many diskussions here in Germany. And I guess, the the silicone-stuff is not always compatible, or? Quote Link to post Share on other sites
RogerH Posted December 28, 2023 Report Share Posted December 28, 2023 (edited) 41 minutes ago, Casar66 said: You mean DOT5.1 or DOT5? We had many diskussions here in Germany. And I guess, the the silicone-stuff is not always compatible, or? The brake seals you buy through all the big suppliers are compatible with Dot 4 or DOT 5. There are no dedicated SBF seals. Roger Edited December 28, 2023 by RogerH Quote Link to post Share on other sites
Waldi Posted December 28, 2023 Report Share Posted December 28, 2023 Thanks all, I will try the nylon brush first, and if not enough, use the honing tools. Cheers, Waldi Quote Link to post Share on other sites
Paul Hig Posted January 3 Report Share Posted January 3 I used one of these https://www.trgb.co.uk/products/brake-servo-tr5-6?_pos=1&_sid=f6355968b&_ss=r Biggest fiddles--- is to adjust the rod that operates the master cylinder doing up the mounting nut behind the throttle peddle!! Refurb .. Apparently the main diaphragms are not available, so may not be possible to refurb Quote Link to post Share on other sites
BlairP Posted January 4 Report Share Posted January 4 I refurbished mine myself, as the diaphragm was in good shape for being 45 years old. A rubber re-conditioner put it back into top form, and everything else was taken apart, cleaned, and reassembled with new seals. It's imminently do-able if the diaphragm's in decent shape. Quote Link to post Share on other sites
Andy Moltu Posted January 4 Report Share Posted January 4 If the bore is scored, it is unlikely the brake fluid affecting the seal will have caused it. More likely the score will be the consequence of grit or other hard material getting in there. Or possibly damage from new during assembly ultimately resulting in leakage as the seals wear and deteriorate over time. It’s ok to use a honing tool to polish the score out if it is not too deep. Quote Link to post Share on other sites
Z320 Posted January 4 Report Share Posted January 4 Hi Waldi, my advice: have a look what possible caused the scratch, to avoid a new one. Ciao, Marco Quote Link to post Share on other sites
Waldi Posted January 4 Report Share Posted January 4 Hi Andy and Marco, this afternoon I used a nylon 19 mm brush with chrome polish on my battery drill, as I was not sure the conventional honing tool stones would make the SS liner worse. It came out perfect after thorough cleaning, I can no longer see or feel the scratch. Since the scratch was not linear but “bended”, I think this was caused during assembly (by Past Parts) or disassembly (by me). No finger-pointing intended. I will install the MC tomorrow but guess it will take a couple of 1000 miles before I know if the issue is resolved. The old seal cup was softer than the one that came in the aftermarket repair kit, so maybe it was attacked by the SBF. Waldi Quote Link to post Share on other sites
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