Installing new piston seal

[rickasbury]

Long story short, have my Kodiak 225 caliper on my bench and I'm trying to put it together. The pictures show that the old piston seal is the same as the new one- I can not get that thing to go into the groove and "pop" in the last little bit. When I have it all pressed in and pushed all the way around, there is about a quarter inch of seal looped up with no where to go...I can't even get the old one to go back in. Also, when I slide the seal over the piston, I expected it to be a rather close fit- this picture is with both the old and the new seal slipped over and it is all kind of sloppy on there...what am I missing here???

 

[alldodge]

Calipers are fairly simple, but have not done any kodiak type. Maybe dingbat can advise

Only use brake fluid, don't use grease or oil, they can make the seals swell

 

[GA_Boater]

A clean caliper body makes a difference. The groove looks kinda grungy and tolerances are tight.

 

[Lowlysubaruguy]

Is the seal a duplicate of the original or is it different. Like mentioned the groove it lives in needs to be cleaned out really well. Just a slight bit of debris will keep the seal from bedding in deep enough.

if all all of that is ok try freezing the seal it may momentarily shrink enough to get it in the groove quickly install it and the piston before it warms up. That’s how some transmission seals have to be installed.

 

[dingbat]

Looks like your trying to fit the “seal” to the housing and the “dust boot” to the piston

 

[rickasbury]

nah, just for illustration.... I reordered the seal as the one ordered was for a 250 caliper and mine is a 225....although they seem to be the same size but I re ordered anyway...maybe the fluid swelled the seal as I could not get the old one in back either....I dun't know....should be here anytime...

 

[rickasbury]

And it arrived and was definitely smaller and popped right in...so the fluid must have swelled the old one....so got it back together no issues yesterday an.....mounted and went to bleed ....to find the master cylinder froze in the closed position. So....ordered a new master cylinder and reverse lock out. On e trailer they show two different cylinders, one each for disk and drum. So the one I had bought from Kodiak parts or something or another by the p/n was the one for drums but the order clearly said disc. E trailer said they were different psi. The lock out I bought from them never worked.. hope the new one does as it's a real pain.....

 

[alldodge]

Don't use a drum cylinder on disk, without modifying it first. Pressures are the same for the most part, the issue is when the brake is released on a disk, all pressure bleeds away from the cylinder. This is done so there is no drag against the disk. A drum cylinder keeps some of the pressure on, but the springs which retract the shoes pushes the cylinders back.

If you have a drum cylinder it can be modified by making a small hole in the valve with a ice pick or such so the master releases all pressure

 

[rickasbury]

It was kind of odd.....as mentioned on E trailer they list the two different ones...on the site I bought the first one, it was only the listing for the part number for the drum, the order said disk. Maybe they modify the one part before they send them out. That site is kodiak brake trailer .com or trailer brake....anyway, I ordered the right one from E trailer and also the reverse lock out. This might explain why my brakes kept locking up in reverse if they were not disengaging or maybe the lock out solenoid was not working...,It was clicking when activated but who knows.....I always had to block it to back up.

Thanks-

 

[rickasbury]

So, did get the new master cylinder installed and bled the brakes . I was not able to pull the trailer until today...if felt like they were working but I did not have a hit the brakes moment. So before I pulled away I did a gentle it the brakes as I had the one caliper apart and assumed it needed to be compressed and check the fluid..it did go down and I topped off. I drove out of the neighbor hood stopping before I got to the highway and checked temps which is around 100- pretty much ambient temp. Drove on to my storage lot, one was up to about 120, the rest around 100. Backed it up and it did not lock up- undid the trailer wire to test and still did not lock up. So, I put it in reverse and gave it the gas hard a couple of times and the brakes started to lock- I looked at the master cylinder was leaking at the fitting for the lockout and it was leaking so I tightened it up- should I assume I also was sucking air in?

 

[bruceb58]

To really see if all the wheels are working equally, do a bunch of stops and measure the temp of each rotor with a temp meter. Should be all around the same. If the one you worked on is cooler than the others, this will tell you.

Regarding the leaking fitting, time to rebleed.