Brake Bias

I just purchased a 1999 VFR 800 less than 2 months ago and I'm loving it. My first bike was a 1986 VFR750F (should have never sold it), then I went to a 2013 R6 before coming back to my current VFR. I have pics below of my new ride.

On to my problem, my brakes have been feeling very poor ever since I purchased the bike. (I think part of it could be that even when new, they probably don't compare to the brakes on a R6.) Shortly after buying the bike, I realized that the left front rotor was covered in oil. I suspect shock oil as the previous owner said the seals were recently replaced.

I replaced all four front brake pads with EBC HH sintered pads, cleaned the rotors with brake clean, and bled the whole brake system. The brake fluid was pretty nasty and obviously old. The fluid from the rear caliper looked like whiskey. I made sure to bleed all points with a vacuum bleeder, then with lever pressure per the maintenance manual.

While the brakes feel marginally better now, they still feel somewhat wooden. The rear brake pedal requires you to almost stomp on it and it feels more like an on/off switch. Whether I use the front brake lever or the rear brake pedal, it feels as though there is more rear brake bias than front. After going on a ride the front calipers are cool to the touch while the rear is almost burning hot. Even the rear wheel get's hot. Does anyone have an idea of what could be causing this such as a proportioning valve? Sorry for the long post. I just wanted to make sure that I covered everything.

 

The fact the disc is getting hot is because the pads are not releasing properly, did you completely clean the return hole

 

On center stand, does back wheel spin freely as it should or is it binding?

 

I haven't checked the return hole and it's work looking into, but both wheels spin free. It doesn't seem as either the front or rear brakes are sticking

 

You reference "wooden brakes".
A 1999...possibly calipers have never been fully serviced before?

I'll submit a full caliper teardown, cleaning of the pistons and bores is called for, resealing as well, obviously followed by correct and proper bleeding.

I'd do all 3. Investment ($$, labor and effort) will yield the results you're looking for.
Don't skimp on your brakes.

 

Thats really strange as I've been thinking the EXACT same thing on MY 2008 ABS VTEC....
I previously had a Fireblade & a 600rr & these are the worse feeling brakes that I've ever encountered. Its not that I don't or can't stop (I keep chirping the rear tyre lol) - its just the lack of feel is appalling....

 

I'm with BBB, when I bought my 01 the PO had neglected the fluid in the clutch and brake lines. Whiskey was a blond compared to the coffee that was in these lines! The two main pistons in the rear clipper were nicked and were rubbing away the seals and gumming up the caliper, so rear brake was like stepping on a block of wood, non-existent! The fronts, although weren't as bad, were definitely not very clean either.

I did a full rebuild front/rear (new seals along with new pistons for the rear) and pulled apart the secondary MC and cleaned and refreshed it and bled the lines. Add this to the EBC HH pads and the stopping power is worlds better! Even if you don't buy new seals, I would place a flat piece of wood in the caliper (thick enough to allow pistons to come out almost all the way) and clean them real good with brake cleaner. When I helped member GoingVFR with his brakes, the front calipers, although seemed to work, the pistons were not coming out evenly. Using the wood method above, we were able to clean around the pistons and move them in and out thereby removing the stiction that was present. That along with lubing the slide pins made the brakes work so much better.

I've heard a few people complain about the 5 Gen and it's linked brakes and even claim that this is the problem but if you research it, the 5 Gen actually had one of the best stopping distances of bikes in that era. Properly maintained and with the right pads, you should be able to stop on a dime and give 9 cents change!

 

I'm not complaining that I can't stop (on a 6th gen) ! It's just that the feel SUCKS..

Calipers all clean, discs all straight - no binding, fluid - fresh, new & clean, EBC HH pads F&R = wooden....

As someone who is a 90% front 10% rear type braker coming off a sports bike onto these I have to say I'm disappointed.

 

Admittedly my '98 5th gen had degraded into delivering that "wooden" feel.... prior to pulling and polishing the pistons, cleaning the bores and removing all traces of old brke fluid.

i have no idea if the PO had ever serviced them...but feel and sensitivity greatly improved after the service.

 

Definitely try rebuilding the calipers, but I wonder if the proportioning valve is gunked up. He there is always a delink

 

Could be a matter of "what you know". All I know are my three bikes, and none of them have a "wooden" feel to me. Although the Ducati will lock up the rear wheel really quick if I'm not careful. The 5 gen seems to have slightly better front braking action than the 6 gen, at least that's how it feels for me. I will say that all three of my bikes have steel braided lines. Does that actually make a difference? Don't know but I'm sure if I hopped on the latest Super bike, I'd go back and slap Honda for making me work so hard just to stop!

That being said, I'm happy with the brakes on both VFRs and even my Duc, but mostly the front brakes there!

 

Thank you for all of the suggestions. I think that they warrant a full rebuild but I was hoping to postpone that till the winter. I think I'll start by pulling the calipers off and re-lubing the sliders, cleaning the pistons, and sanding any glaze off of the pads.

Where is the proportioning valve located? Is it the attachment on the left front caliper, or at the center bleeder location under the tank?

 

I bolded the key thing with me. I've ridden the new S100RR and all three Panigales and they all have brakes that will slow the bike by simply blowing on the lever. I doubt I could ever get that level of brakes from the 5th gen, but something close would be great.

ETA: As my bike has 69000 miles on it, I'm sure deeply going through the brake system would help a lot tho. I've got new EBC wave rotors front and Galfer pads, the rear is a Glafer wave rotor and Galfer pads. I may change them all out to EBC HH when they get worn. All the pads are new right now, so that will be a while.

 

On the 5 Gens, there is a delay valve on the right fork, then there's the Secondary master cylinder on the left fork and the Proportioning valve under the seat above the rear master cylinder.

 

If the fluid looks that bad, the chances are that the whole system is full of crap.
No amount of bleeding will fix that, you need to strip the whole lot and clean, including the front slide pins.
Age has something to do with it as well, it's why I did this:

 

Very nice. Fork swap and delink should be the first mod on any vfr800

Sent from my Nexus 6 using Tapatalk

 

Any ?

Even the ones with ABS >?

 

Yup, especially the ones with abs. It adds so much unnecessary weight, clutter, maintenance, complexity and failure points. I am much more of a fan of proper braking technique, rather than just ham fisting the controls and hoping that the electronics can sort it out.

 

... this could become another oil thread with all this linked vs delinked vs abs talk ... where's BB at??

 

Off somewhere beating up SOW lol