Question: Would the increased pressure from new brake components be enough to blow out fork seal? Or is this just coincidence?
1984 FJ1100. 25,000 miles. Anti dive units in place.
I recently changed out the front brake rotors, brake pads, front master cylinder piston (had a leak), and brake fluid. Took bike for a test ride and the fork seal completely blew out of its seat. My concern is once I replace seal could it happen again, meaning is there something else wrong in fork, or maybe anti-dive unit?
They are unrelated. That fork seal was going to blow out with the old brakes. Look closely at the seal, it has to be damaged to blow past the retaining ring. Or the ring failed and the seal might still be good.
I've seen quite a few seal retaining rings that were nothing but rust residue.
Hopefully the fork juice did not contaminate your new pads.
Quote from: ibrcrosspein on September 03, 2015, 02:01:26 PM
Took bike for a test ride and the fork seal completely blew out of its seat.
The actual oil seal blew out or the dust seal on the top?
Randy - RPM
Quote from: FJmonkey on September 03, 2015, 02:29:15 PM
They are unrelated. That fork seal was going to blow out with the old brakes. Look closely at the seal, it has to be damaged to blow past the retaining ring. Or the ring failed and the seal might still be good.
Seal seams to be in good condition; seal has a firm grab on fork tube, no pitting or cracks. Retaining circlip has some surface corrosion but is still functional and its groove in the slider tube is clear of rust and debris.
Quote from: racerrad8 on September 03, 2015, 03:34:27 PM
Quote from: ibrcrosspein on September 03, 2015, 02:01:26 PM
Took bike for a test ride and the fork seal completely blew out of its seat.
The actual oil seal blew out or the dust seal on the top?
Randy - RPM
The seal came out along with the parts above it, washer, circlip, and dust cover
Hopefully these pictures will be better.
Okay, you might have one too many washers in there.
The original seals where shorter and they used two washers. So, put a washer down into the fork first. that protects the seal from the lower fork tube bushing from raising the seal if it were to get that extended.
Then drive the seal in and look at the distance from the top of the seal to the groove.
If the groove is right at the seal, put in the snap ring, if it is the thickness of the second washer then add the second washer.
I have had a few come in with the extra washer installed and the snap ring was just inside the bore and not actually in the groove.
Randy - RPM
When I did the conversion form '85 front end to '89 front end I had to delete a washer as Randy says above.
The '85 had a washer on both sides of the oil seal. Only one (below the seal) would fit in the '89 sliders.
Spacing allowed for the washer above the seal with the retaining clip fitting snugly in its groove. I am going to put everything back in, change fork oil and take it for a gentle test ride. Thanks everyone for the help.