Just went to take the rear brake caliper apart to check its state and it seems to be seized. I took my air compressor with 90-100psi in it and used that and the cups wouldnt budge at all.
What are my choices? Ebay or Econco?
Put a grease nipple in place of the bleed screw, block the banjo fitting and use a grease gun to push out the pistons
This has worked for me as well. Try and make both pistons come fully out at the same time otherwise you will no longer be able to put pressure on remaining piston.
2 things:
1: throw some heat at it. not ridiculous, but it will def help. plan on replacing the seals of course. :twocents:
2: clamp piston on fitting side in and blow 'inboard' piston out. then, take clam-shells apart. use thin piece of aluminum (like flashing) and block 'crossover' hole in caliper body. reassemble caliper but with one half up, other down. un-clamp 'outboard' piston, then blow into fitting. 2nd piston out. ive never had an issue doing it this way.
ok thanks for the advice guys. I'll have a go at it this weekend.
It's the last thing I needed to get sorted before I can put it all back together to iron out any bugs then take it to the shop for some tires and a safety so that I can insure it. Then it's good to go for Deals Gap :clap:
John
Quote from: rd400canuck on February 27, 2020, 08:29:10 PM
ok thanks for the advice guys. I'll have a go at it this weekend.
It's the last thing I needed to get sorted before I can put it all back together to iron out any bugs then take it to the shop for some tires and a safety so that I can insure it. Then it's good to go for Deals Gap :clap:
John
I cant wait! It'll be a first for me too!
We've been dealing with stuck calipers for at least 20 years...Mark explained it well with removing one side at a time.
ANYTIME when using compressed air always wrap in heavy towels...
Chuck
Yes, I'm looking forward to Deals Gap and meeting you guys!
I USUALLY AIM IT DOWN INTO A 2 OR 5 GALLON BUCKET FILLED WITH RAGS. sorry caps. yeah, they can be a missle.
And that's why using a grease gun, or the master cylinder to push them out. Much safer than compressed air, and also gives much higher pressure, if required.
never found the need. air will do it.
If using a stock rear RD400 master cylinder you must take out the brake fluid supply line fitting out of the master cylinder and make sure the tiny hole is clean. There is 2 under there going into the piston bore.
That tiny hole will cause the brake caliper not to retract all the way, then drag and build heat, then seize.
Always use new pads and throw the anti-rattle shims in the trash and don't use them!
Check disk for runout anything over .015 in. is not good.
Tips of the day...
Chuck
I should add this also...due to the OEM RD400 rebuild kit no longer available from Yamaha part # 1A1-20000-50-00
When needing to rebuild the RD400 rear master cylinder, use a OEM Yamaha FJ 1100-1200 kit but re-use the stock RD shaft and not the FJ shaft.
All your using is the rubber parts from this kit.
Yamaha Part # 2YK-W0042-50-00 about $50.
Chuck
Awesome... thanks for all the input and knowledge as always :clap:
Hopefully this weekend all is successful and I can get them out of the caliper. As far as the master I have gutted that as well... I dont know what was in there but it look like saw dust when I removed the oil feed line. I have rebuild kits for the caliper and master from Econo ready to be ordered. I just want to get a look at the cup surfaces once I get them out to make sure they are not pitted.
John
A soak in Evaporust for a day or two with the caliper submerged wouldn't hurt either. Love that stuff! I've done it both ways: my take- grease takes longer and is messier, air pressure nozzle from compressor is way faster and easier. Never had one that wouldn't come out with air. Stubborn ones will come out after 10-15 seconds or so. Rag on the projectile side. Good luck and whip that task!
Alright guys.... I followed everyone's advice, went and bought a rubber tipped gun and they came out. They put up a fight though but they finally gave in. Thankfully the cups look fine... a little pitting towards the top but none of it near where the seals touch.
Now I need to ask... how the hell do I clean the track on the inside where the seal goes without scratching it up? It's full of old rubber bits that wont come off.
Dremel with wire wheel attachment.
yup. ^ works every time. :clap:
Bought some and put them in the drill press... worked like a charm :)
Quote from: Evans Ward on February 29, 2020, 07:06:11 PM
Dremel with wire wheel attachment.
Quote from: m in sc on February 29, 2020, 07:48:26 PM
yup. ^ works every time. :clap:
Need to clean out some stubborn corrosion/deposits on a caliper seal groove so I'm going to pick up some Dremel bits. The ultrasonic had no effect on it.
What do you recommend for wire wheel type? Brass, steel, or stainless?
Quote from: SoCal250 on October 01, 2020, 06:17:02 PM
Quote from: Evans Ward on February 29, 2020, 07:06:11 PM
Dremel with wire wheel attachment.
Quote from: m in sc on February 29, 2020, 07:48:26 PM
yup. ^ works every time. :clap:
Need to clean out some stubborn corrosion/deposits on a caliper seal groove so I'm going to pick up some Dremel bits. The ultrasonic had no effect on it.
What do you recommend for wire wheel type? Brass, steel, or stainless?
Brass. There was a vendor at an auto show I went to last year selling brass Dremel brushes cheap I bought a handful and used them up over the year. They did a great job along with my 90 degree 1/8" chisel I made out of some spring steel.
This is going to sound ridiculous but, note when using wire dremel brushes, only use on low speed. They will rip apart rather easily and the small wires are a pain to clean. I recently had one get stuck in my foot and had to have a surgeon remove it. (I know ridiculous) but when I looked I found those wires all over from cleaning up rusty parts.
this is a good point. ive had them fly apart as well. low speed for sure. ever had a needle stuck in your eyeball to remove material when they find the rust ring? (steel wheel) even when you were wearing safety glasses? i have. don't recommend it.
The wire brush treatment is good for the interior walls but for the seal lands I use stainless dental picks and scrape the lands by hand. Does a better job and gets all the rust out.
Lyn Garland
I only use a $9 Harbor Freight wall-wart powered tool for the brushes. Not enough speed or power to do real damage. I even use it with a sanding drum to do the Bert Munroe thing to a gnarley toenail.
There is a product used to hold fiberglass insulation bats between floor joists called "lightning rods" - VERY stiff spring steel with sharpened ends. Bend one to a 90 and shape a blade on about 1/8" sticking out. Makes a great tool for getting into the seal recess. Just don't get carried away and gouge the aluminum.
I use dental picks like Lyn. Found them at a home show years ago for cheap as they were factory seconds, completely stainless. You may be able to get used ones from your dental hygienist, but in my experience they were pretty worn. I've found similar picks at hardware stores but they had plastic handles which didn't hold up well at all.
Can get dental picks on ebay.
Thanks for the advice. :thumbs: I have stainless dental picks so I'll give those a try. The caliper I'm working on is completely clean and smooth in the piston bore, but the seal groove is another story.
Also heard/read somewhere to use Simple Green and a green Scotch pad to remove the crystalized brake fluid. Seems to work well.
Quote from: motodreams on February 27, 2020, 04:40:10 PM
This has worked for me as well. Try and make both pistons come fully out at the same time otherwise you will no longer be able to put pressure on remaining piston.
My caliper is also frozen heat and air won't move it.
I was going to try a grease gun but the standard zerk fitting threads are too small to fit the bleeder bolt hole /threads.
Do you happen to know what size zerks I need to order to get these suckers out? Thanks
"DISREGARD" I found some stuff in my stash and was able to get them out with grease - now the fun part cleaning the seal grooves. :clint:
Quote from: forexer on February 10, 2021, 08:24:45 PM
Quote from: motodreams on February 27, 2020, 04:40:10 PM
This has worked for me as well. Try and make both pistons come fully out at the same time otherwise you will no longer be able to put pressure on remaining piston.
My caliper is also frozen heat and air won't move it.
I was going to try a grease gun but the standard zerk fitting threads are too small to fit the bleeder bolt hole /threads.
Do you happen to know what size zerks I need to order to get these suckers out? Thanks
"DISREGARD" I found some stuff in my stash and was able to get them out with grease - now the fun part cleaning the seal grooves. :clint:
Great! I made a tool with very stiff ~3mm wire bent 90 degrees, cut, and ground to a chisel point. I use it to clean the groove and press Scotchbrite in to polish it. Then make sure plenty of brake cleaner and rags to clean out ang grit.