Wildguzzi.com
General Category => General Discussion => Topic started by: canuck750 on November 10, 2014, 09:54:00 PM
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I pulled the front calipers off the 850T I bought this spring to check them out for the 750S tribute I am going to build. The previous owner was riding this bike on a semi-regular basis before I bought it so I was just planning on new pads and perhaps seals and hoses.
Getting the pistons out took an hour + in the ultrasonic cleaner and lots of air pressure, tapping with a rubber hammer and sprays of brake cleaner. The pistons were seized in the castings.
The pistons are toast, deeply pitted with rust, the castings cleaned up pretty good with a bead blast and an hour back in the ultrasonic cleaner.
(http://i249.photobucket.com/albums/gg217/canuck750/74%20V7%20Sport/DSC03956_zps9d8b24e0.jpg) (http://s249.photobucket.com/user/canuck750/media/74%20V7%20Sport/DSC03956_zps9d8b24e0.jpg.html)
(http://i249.photobucket.com/albums/gg217/canuck750/74%20V7%20Sport/DSC03959_zps3928042b.jpg) (http://s249.photobucket.com/user/canuck750/media/74%20V7%20Sport/DSC03959_zps3928042b.jpg.html)
Master cylinder leaking out the ram face
(http://i249.photobucket.com/albums/gg217/canuck750/74%20V7%20Sport/DSC03961_zpse5b34317.jpg) (http://s249.photobucket.com/user/canuck750/media/74%20V7%20Sport/DSC03961_zpse5b34317.jpg.html)
The pins are all rusted and the piston seals are done, the brake hoses are soft and stretched.
(http://i249.photobucket.com/albums/gg217/canuck750/74%20V7%20Sport/DSC03963_zps60ca2d23.jpg) (http://s249.photobucket.com/user/canuck750/media/74%20V7%20Sport/DSC03963_zps60ca2d23.jpg.html)
I should have just bought new calipers off MG Classics but I want the dual bleeder bodies for this bike.
Can't believe the old T was able to stop at all!
If you have a 40 year old Guzzi I suggest you take a good look at the calipers, hopefully they are not as far gone as this pair.
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Typical of any calipers still with the original chrome plated pistons. Heating the caliper body will usually help pop them out.
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Good advice Charlie, hadn't thought of good old heat.
Any tips for rebuilding these old calipers?
I am considering powder coating the castings or trying that fancy brake caliper paint that the car shops sell, I want to use a paint that will resist brake fluid. Have you tried any of that special caliper paint?
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DuPont Imron, and possibly many other 2-part polyurethane paints, resist brake fluid very well. In fact Imron resists any solvent I've gotten on it, including lacquer thinner and acetone, as well as gasoline and the glycol based brake fluids. Just don't breathe the stuff while you're spraying it. DuPont Corlar epoxy primer is the stuff to use as a base coat.
Today's powder coats may be just as good for a brake caliper, but I haven't used them yet.
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Good advice Charlie, hadn't thought of good old heat.
Any tips for rebuilding these old calipers?
Yep, buy new calipers from MG Cycles. Last year when going through my 850T I had the same problem. Started adding up the prices for all the rebuild part (seals, pistons, pins, pads, bleed nipples) and found that for about $20 to $30 more I could just buy a new caliper that already had updated anodized pistons, new pads and pins and a warranty. If I were to try and rebuild there was no guarantee the end product would work. Its a pretty easy choice. Then you can always sell you old one on eBay for $10 or $15 each and the deal is even better.
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Yep, buy new calipers from MG Cycles.
But, Jim says he wants to stick with the dual-bleeder calipers.
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One tip for the rebuild of a caliper is to be sure the square cut groove for the seal is cleaned up well and not heavily pitted. Even though the seal will deform some to seal, it is better it make sure you have that area squared away before paint. Mike
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But, Jim says he wants to stick with the dual-bleeder calipers.
Doh! I didn't read the last bits of the post.
What's the advantage of dual bleeders?
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Doh! I didn't read the last bits of the post.
What's the advantage of dual bleeders?
No real advantage function-wise IMO.
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I am partial to using the grease gun method on stubborn pistons. A bit of a mess to clean up but not to bad. I have had good luck with powder coat on calipers.
(http://img.photobucket.com/albums/v199/Hahnda/Guzzi%20850T/IMG_1070_zps263c28ae.jpg)
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Stripped my calipers during a recent overhaul; the front pair of pistons were anodised but the rear two bleeder had the chromed ones.
After 34 years I amazed they looked so good, and I've reused them.
I got my calipers and front disc carriers coated with brake fluid resistant coating, although I was told the gold colour was the least resistant of these coatings. During the final bleed I didn't notice the bit of fluid that dripped down one caliper and it must have soaked in for days before my attempt to clean it off. Luckily it's not noticeable, so I'll live with it.
(http://i845.photobucket.com/albums/ab18/Stevex998/IMG_0805_zpsc08ec746.jpg) (http://s845.photobucket.com/user/Stevex998/media/IMG_0805_zpsc08ec746.jpg.html)
(http://i845.photobucket.com/albums/ab18/Stevex998/IMG_0802_zpsf4c98620.jpg) (http://s845.photobucket.com/user/Stevex998/media/IMG_0802_zpsf4c98620.jpg.html)
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I bought a pair of new Brembo calipers for my Eldorado but wanted to try and preserve the original ones for my 750S3 and 750S clone. The original bikes used dual bleeder Brembo calipers to keep the S3 original and if they worked out then do the same on the 750S bike.
(http://i249.photobucket.com/albums/gg217/canuck750/Moto%20Guzzi%20750%20S3/PA090003_zpsc60306ea.jpg) (http://s249.photobucket.com/user/canuck750/media/Moto%20Guzzi%20750%20S3/PA090003_zpsc60306ea.jpg.html)
The other thing I noticed on the S3 that is different from the 850T is the S3 has steel lines from the front calipers then rubber hoses, the 850T has rubber hoses direct to the caliper.
(http://i249.photobucket.com/albums/gg217/canuck750/Moto%20Guzzi%20750%20S3/PA090002_zpsaacbe750.jpg) (http://s249.photobucket.com/user/canuck750/media/Moto%20Guzzi%20750%20S3/PA090002_zpsaacbe750.jpg.html)
This is a picture of the 850T front caliper and hoses
(http://i249.photobucket.com/albums/gg217/canuck750/74%20850T/P6050006_zpsace43323.jpg) (http://s249.photobucket.com/user/canuck750/media/74%20850T/P6050006_zpsace43323.jpg.html)
Anyone know what other Guzzi would use the same rubber hoses as the 750 S3?
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Lemans 1 perhaps? T3 has taller bars, so the front brake hose length is different . Also the presence of a spitter for the brake light switch is another factor to consider
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This is a picture of the 750S3 hose routing
(http://i249.photobucket.com/albums/gg217/canuck750/Moto%20Guzzi%20750%20S3/PA080039_zps23f0388f.jpg) (http://s249.photobucket.com/user/canuck750/media/Moto%20Guzzi%20750%20S3/PA080039_zps23f0388f.jpg.html)
and the splitter and brake light switch
(http://i249.photobucket.com/albums/gg217/canuck750/Moto%20Guzzi%20750%20S3/PA080038_zps900f5f32.jpg) (http://s249.photobucket.com/user/canuck750/media/Moto%20Guzzi%20750%20S3/PA080038_zps900f5f32.jpg.html)
I may just bundle up the hoses and send them to Curtis Harper to see if he can match them.
The 850T routes a hose from the master cylinder
(http://i249.photobucket.com/albums/gg217/canuck750/74%20850T/P6050018_zps5d16d8c4.jpg) (http://s249.photobucket.com/user/canuck750/media/74%20850T/P6050018_zps5d16d8c4.jpg.html)
and down to the splitter on the lower triple and both front hoses connect to the other side of the splitter, I am assuming this is how the dual disc V7 Sport and 750S routed the brake lines?
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Seems they would all be the same as a T3 except for the one from the front master cylinder to the splitter.
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If you want to upgrade to stainless, Teo Lamers has S3 kits with black outer coating. Saw some on their site a while back when purchasing the 750S kit from them
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Does the S3 have linked brakes? I'd think not, and this might preclude using hoses from T3 and later..
Peter
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Does the S3 have linked brakes? I'd think not, and this might preclude using hoses from T3 and later..
Peter
Pretty sure it does. S3 is just basically a T3 with sporty bodywork IIRC.
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My '82 Ducati 900SS appears to have the same rubber to steel line set-up as pictured on the S3. Are there steel hose mounts which are bolted through the fender mounting holes in the forks? Perhaps Bevelheads might have them.
Peter
https://store.bevelheaven.com/front-brake-line-kits/
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I bought a pair of new Brembo calipers for my Eldorado but wanted to try and preserve the original ones for my 750S3 and 750S clone. The original bikes used dual bleeder Brembo calipers to keep the S3 original and if they worked out then do the same on the 750S bike.
(http://i249.photobucket.com/albums/gg217/canuck750/Moto%20Guzzi%20750%20S3/PA090003_zpsc60306ea.jpg) (http://s249.photobucket.com/user/canuck750/media/Moto%20Guzzi%20750%20S3/PA090003_zpsc60306ea.jpg.html)
The other thing I noticed on the S3 that is different from the 850T is the S3 has steel lines from the front calipers then rubber hoses, the 850T has rubber hoses direct to the caliper.
(http://i249.photobucket.com/albums/gg217/canuck750/Moto%20Guzzi%20750%20S3/PA090002_zpsaacbe750.jpg) (http://s249.photobucket.com/user/canuck750/media/Moto%20Guzzi%20750%20S3/PA090002_zpsaacbe750.jpg.html)
This is a picture of the 850T front caliper and hoses
(http://i249.photobucket.com/albums/gg217/canuck750/74%20850T/P6050006_zpsace43323.jpg) (http://s249.photobucket.com/user/canuck750/media/74%20850T/P6050006_zpsace43323.jpg.html)
Anyone know what other Guzzi would use the same rubber hoses as the 750 S3?
I think that the 75 Eldorado would use the same rubber hoses with single disk....
Mark
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Speigler (and others like Earl's) can make to order just about hose that you want. So unless you gotta' have original style rubber hoses, sourcing them isn't really a problem.
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Speigler (and others like Earl's) can make to order just about hose that you want. So unless you gotta' have original style rubber hoses, sourcing them isn't really a problem.
I want to get the stock hoses for the 750S3, 'preservation' of original equipment is what I am aiming for. I want to keep the original paint and only change out what is worn out, dangerous or too ugly to bear (re-chrome the shiny bits, replace the rubber parts, polish the aluminum rims and stainless fenders, new cables, hoses, clamps etc...)
Cheers
Jim
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Jim, I replaced the left hand front brake pipe line which I bought a from Larry Klein of gt motors in Lansing.
That was about a couple of years ago.
Luca
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Jim, I replaced the left hand front brake pipe line which I bought a from Larry Klein of gt motors in Lansing.
That was about a couple of years ago.
Luca
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I always use grease to remove stuck pistons now. I saw a piston fly across the workshop using compressed air a few years ago, could do all sorts of damage to man or machine :-\
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I always use grease to remove stuck pistons now. I saw a piston fly across the workshop using compressed air a few years ago, could do all sorts of damage to man or machine :-\
:+1
When I tell people about this method they ask me why isn't more widely known. Dunno. No flying pistons. Its so easy and works great. No the threads don't match up on the the grease gun and the caliper but they are REALLY close. I have never screwed up threads using this method.
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A shop rag wrapped around the caliper half will catch the piston. Never had one fly anywhere...
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A shop rag wrapped around the caliper half will catch the piston. Never had one fly anywhere...
Very true. I try air first but if its truly stuck out comes the grease gun.
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Compressed air is a legitimate method, but I'll cast my vote for the grease gun. Not only is it capable of putting out approximately 100 times the pressure of shop air, but it's very safe, as long as you take normal precautions like wearing goggles. When I wanted to pressure test the 80 gallon air tank of the 2-stage industrial air compressor I was given, I filled it with water and plumbed a gauge and a Zerk fitting. It took two tubes of grease to do it, but I got it up to over 300 psi safely, and put it in service.
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ok I didn't mention we were all stoners back then. we did get a laugh outoff the flying piston tho. off topic but how many of you have had trouble getting the beads seated with quad tire? I can give you all a secret if you like
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Very true. I try air first but if its truly stuck out comes the grease gun.
Never needed anything more than heat and 120 psi. <shrug>
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Got in some garage time today and rebuilt the pair of Brembo calipers and master cylinder
All of the rebuild kits were bought on line from MG Cycle
Powder coated the caliper castings with my DIY home kit
(http://i249.photobucket.com/albums/gg217/canuck750/74%20850T/DSC04115_zps50a30e9e.jpg) (http://s249.photobucket.com/user/canuck750/media/74%20850T/DSC04115_zps50a30e9e.jpg.html)
New inner and outer caliper seals
(http://i249.photobucket.com/albums/gg217/canuck750/74%20850T/DSC04116_zps2cee1c04.jpg) (http://s249.photobucket.com/user/canuck750/media/74%20850T/DSC04116_zps2cee1c04.jpg.html)
(http://i249.photobucket.com/albums/gg217/canuck750/74%20850T/DSC04118_zpsdf257a02.jpg) (http://s249.photobucket.com/user/canuck750/media/74%20850T/DSC04118_zpsdf257a02.jpg.html)
Anodized pistons
(http://i249.photobucket.com/albums/gg217/canuck750/74%20850T/DSC04120_zps5dc48ef8.jpg) (http://s249.photobucket.com/user/canuck750/media/74%20850T/DSC04120_zps5dc48ef8.jpg.html)
Bleeders
(http://i249.photobucket.com/albums/gg217/canuck750/74%20850T/DSC04121_zps59143e8c.jpg) (http://s249.photobucket.com/user/canuck750/media/74%20850T/DSC04121_zps59143e8c.jpg.html)
O ring between castings
(http://i249.photobucket.com/albums/gg217/canuck750/74%20850T/DSC04123_zpsa0a781b4.jpg) (http://s249.photobucket.com/user/canuck750/media/74%20850T/DSC04123_zpsa0a781b4.jpg.html)
Locktite the new bolts
(http://i249.photobucket.com/albums/gg217/canuck750/74%20850T/DSC04129_zps760d48f0.jpg) (http://s249.photobucket.com/user/canuck750/media/74%20850T/DSC04129_zps760d48f0.jpg.html)
Grease the piston seals
(http://i249.photobucket.com/albums/gg217/canuck750/74%20850T/DSC04127_zps24474027.jpg) (http://s249.photobucket.com/user/canuck750/media/74%20850T/DSC04127_zps24474027.jpg.html)
New pins
(http://i249.photobucket.com/albums/gg217/canuck750/74%20850T/DSC04126_zps4ee3f497.jpg) (http://s249.photobucket.com/user/canuck750/media/74%20850T/DSC04126_zps4ee3f497.jpg.html)
(http://i249.photobucket.com/albums/gg217/canuck750/74%20850T/DSC04128_zps52d4c88e.jpg) (http://s249.photobucket.com/user/canuck750/media/74%20850T/DSC04128_zps52d4c88e.jpg.html)
Master cylinder kit
(http://i249.photobucket.com/albums/gg217/canuck750/74%20850T/DSC04131_zpsc4a4be74.jpg) (http://s249.photobucket.com/user/canuck750/media/74%20850T/DSC04131_zpsc4a4be74.jpg.html)
And an easy job done
(http://i249.photobucket.com/albums/gg217/canuck750/74%20850T/DSC04132_zpsd9049d75.jpg) (http://s249.photobucket.com/user/canuck750/media/74%20850T/DSC04132_zpsd9049d75.jpg.html)
Buying new ones is probably more cost effective if you value your time at all but I want to keep the original 2 bleeder calipers on the 750 S3
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Maybe late to the party, but your brake lines look exactly like my 76 Convert. Lots of kits around for them. :BEER:
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Yes, the F08 was the stopper for about all of the early disk brake models. calipers have gotten fancier over the years, but I'm not convinced that they've gotten any better.
Sometimes you go though the rebuild instead of new purchase because there's a value to the exercise and experience. Also, ANYONE can replace parts. Sometimes it's a matter of pride to do an overhaul -- just because you can.
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Yes, the F08 was the stopper for about all of the early disk brake models. calipers have gotten fancier over the years, but I'm not convinced that they've gotten any better.
Sometimes you go though the rebuild instead of new purchase because there's a value to the exercise and experience. Also, ANYONE can replace parts. Sometimes it's a matter of pride to do an overhaul -- just because you can.
;-T ;D
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Nice job Jim
The old (smal logo) parts are like gold here