Need help identifying motortrike irs disk brakes

[rodekyll]

I misunderstood. I thought you meant the caliper sliders.

I got the rods sized and installed and went for a ride. I didn't do much with the proportioning valve due to traffic. Nothing notable about the ride except that it was darn hot in East Texas today. When you're road testing brakes that's a good thing. Not the hot part; the other part.

 

[lgjhn]

The owner of the MT that I worked on swung by my shop today just to pay a visit...and to thank me again for fixing his brakes....LOL. He said: "Now just look how nice, bright & shiny those back rotors are now. They've NEVER been like that since I triked it. When I step on the brake pedal now, she definitely stops." FWIW, he's ridden that MT with marginal rear brakes ever since it was originally triked out 8 years ago, that's including 2 trips to Alaska and back like that....geez. He's a 70-year-old Vietnam war vet, who doesn't mess with computers, but he sure LOVES that purple trike. I think I've made a friend for life and will probably get all his future maintenance business....

 

[rodekyll]

You're inspiring me to try another bleed. My disks don't get shiny. :blush:

 

[LarryA]

the caliper/pistons on the 85 dodge datona brakes i am using on my trike (rear) uses a square cut o -ring....the o-ring groove in the caliper bore is cut on a slight taper....maybe to make the piston retract slightly when pressure is released. the piston should creep out over time as the pads wear. but normal operation sees the o-ring stretch sideways a small amount upon brake application......If you hav'nt changed o-rings, I would....swollen o-rings could use up a lot of m/c pressure, leaving less for the application. my .02

 

[Jack Klarich]

the caliper/pistons on the 85 dodge datona brakes i am using on my trike (rear) uses a square cut o -ring....the o-ring groove in the caliper bore is cut on a slight taper....maybe to make the piston retract slightly when pressure is released. the piston should creep out over time as the pads wear. but normal operation sees the o-ring stretch sideways a small amount upon brake application......If you hav'nt changed o-rings, I would....swollen o-rings could use up a lot of m/c pressure, leaving less for the application. my .02

Good point Larry, this is what we called piston cocking

The O ring does 2 jobs

1 Seals the piston to caliper so you build pressure ( no leakage)

2 Allows the piston to slightly retract when pedal pressure is released

If not for #2 working properly you would hang a piston ( cocking and piston would not retract) brakes sticking pads worn uneven Bore of caliper would be scored with piston wearing also

Dodge in their infinite wisdom years ago used pistons made of bake light material to cut down on heat and scoring

That did not work good when the fluid was contaminated

We had to break the pistons to get them out ( before there were loaded or reman calipers)

 

[LarryA]

just a few more thoughts.....to be taken with a grain of salt...if brakes are car based. the friction compound may be less "grabby" than a motorcycle pad....because the auto may have a brake booster and be stopping a heavier vehicle. If you could just try 1 puck per wheel, or could file a cross hatch on the pucks ie, reducing pad area, thus increasing unit pressure at the disc. or if u could try motorcycle pad mtl. on the pucks? This is assuming u can locate replacement pucks if this does not work out .... drilled or slotted rotors may help also. sounds like your hydraulic ratios are sorted out...what you need is some friction. good luck on an interesting problem!

 

[LarryA]

Jack....yes the datona has bakelite pistons I had the calipers apart for about 6 mo during the build, but the car had sat for 15 yrs. prior, I had to chuck up the pistons in the lathe and sand very lightly to get them to fit in their bores. using bakelite may not have been Chrysler's finest moment!:xzqxz:

 

[rodekyll]

I did yet another bleed with no change. However, on my predetermined brake test route I am stopping in a shorter distance since I started experimenting with the adjustable proportioning valve. I might be getting somewhere.