Rear brakes seized

Catmandu2 said:
So,,, digging into the smc a bit,,, I got the rubber boot off, and found this pile of rust dust crud on top of the pushrod. Intially, I thought that the snapring was corroded away,,, but after a bit of cleaning I see that it is intact. Funny,,, once I put a bit of penetrating oil to soak in on the snapring,,, the rear brake freed up !! Not sure if I will pop the piston ***'y out before I have replacements in hand. That could take a while,, because I get my Honda spares state-side, where they are %40-50 less $$$,,, Cat'

Click to expand...

Yup, precisely how it's not supposed to look.

Check around on pricing as I did mine a year ago and dealer quoted me substantially less. That being said ... I opted to replace the piston as I could not confirm if there has been any change to the cylinder design. I lightly polished the cylinder with some rubbing compound before reassembly and was pleased with the results.

This thread has reminded me again to peel back the boot and reapply some brake grease for the winter.
 
Good point,, Rod,
I also had a hard braking event,,, just prior to my rear brake acting up. And at the moment,,, I can't really even see the piston,,, as it is caked in gunk. My reference to not stomping on the brake pedal was because I did not want to shoot the piston out by applying hydraulic pressure behind it. I suppose that with some cleaning,,, and perhaps some warming (hot air gun),, the spring may "un-stuck" it. I am still looking for a good price on a new unit,,, but this is something to do in the mean time. Cat'

drrod said:
Interesting that you should say "stomp on the brake pedal"..... My current bike (04) had 72,000kms on it when I got it. I had just gotten rid on an 04 with 190,00 kms. My old bike never had a hint of a brake problem. On my way home, with the new bike, I had a left turner. Hit the brakes HARD. Within 100 yds of doing that, the rear brake started to hang up. Almost locked solid in the 2 miles it took to get home. When I took it apart, the SMC piston was seized solid. The bore above the piston was clean. I didn't even try to take the piston out or rebuild it, just replace the whole SMC. Incidentally, the previous owner had not a hint of brake problems. The brakes had been serviced religiously while he owned it.

Theory....the previous owner had not really used the brakes hard and when I did, it forced the piston into an area of the bore that was not been used very much (if at all). Result - piston got hung up for some reason.

Take home .........use the brakes hard and often:D ie. take them to the gym to keep them in shape.

Rod
Click to expand...
 
I flushed the clutch and brake system last night and just finished putting everything back together. At 165,000 miles it's the 14th time I've done the brakes and maybe 20 times for the clutch as I sometimes do the clutch at half the distance when I see the fluid getting much different color than the brake side of the system.

I was pleased to see no changes under the boot - still looks good. I just fit the boot back into place and leave it dry. I live a few miles from the beach in Florida and often ride in rain and wash the bike often. I guess I got a good SMC from the factory but I'm prepared to replace it when necessary. One thing I did this time I've not done before is measure the SMC compression travel pre and post flush. There was no change but the distance is compresses did surprise me. It compresses barely 1.5mm by hand but this is enough to prevent turning the rear wheel with my foot.
 
Not having my replacement SMC as yet,,, I decided to clean up and reassemble the top end components back into the original smc,,, essentially the push-rod, boot and clevis. With all the corruption that had accumulated I can see that the short actuating stroke could easily be impeded. Stopping power is going to push the piston down as far as it can,, much more than we can do by hand. But contamination at the intersection space between the push-rod and it's circular keeper plate,, and at the rounded nose of the push-rod where it contacts the cupped piston end, will prevent the piston from returning to it's full rest position. This would cause the rear brake to drag,, or even lock up. I believe that is what happened me. Anyway,, after a good cleaning,,, and filling the upper assembly with high temp synthetic brake grease,, it tested out fine on a 30 minute test ride ride, with lots of braking. Before putting it all back together, I did check the piston movement. It was about 1.5mm by hand,, and the same after full assembly. I could not check the full piston stroke,, as I had never opened up any of the hydraulics. Anyway,,, I have the whole winter to find a replacement for the old SMC. Maybe I will move on to coolant leaks, for a while,,,,, Cat'

dduelin said:
I flushed the clutch and brake system last night and just finished putting everything back together. At 165,000 miles it's the 14th time I've done the brakes and maybe 20 times for the clutch as I sometimes do the clutch at half the distance when I see the fluid getting much different color than the brake side of the system.

I was pleased to see no changes under the boot - still looks good. I just fit the boot back into place and leave it dry. I live a few miles from the beach in Florida and often ride in rain and wash the bike often. I guess I got a good SMC from the factory but I'm prepared to replace it when necessary. One thing I did this time I've not done before is measure the SMC compression travel pre and post flush. There was no change but the distance is compresses did surprise me. It compresses barely 1.5mm by hand but this is enough to prevent turning the rear wheel with my foot.
Click to expand...
 
I wonder if the VFR ones are the same as there seem to be lots of these up for sale on various sites ,might be worth looking into .
 
Putting my air box assembly back in place now. And I am wondering if using an anti-seize product (aluminium or copper based) on the JIS-phillips-head screws that secure the box to the throttle bodies,, is a good idea. They do get stuck,, probably due to the dissimilar materials,,, and I am replacing a couple that were in rough shape. The copper based anti-seize is for heat applications,, and is recommended for sparkplug threads. Anyone tried this,, or other products, with success ?? Cat'
 
Last edited:
Catmandu2 said:
Putting my air box assembly back in place now. And I am wondering if using an anti-seize product (aluminium or copper based) on the JIS-phillips-head screws that secure the box to the throttle bodies,, is a good idea. They do get stuck,, probably due to the dissimilar materials,,, and I am replacing a couple that were in rough shape. The copper based anti-seize is for heat applications,, and is recommended for sparkplug threads. Anyone tried this,, or other products, with success ?? Cat'
Click to expand...

If you have a set of JIS screwdrivers, and put just a drop of either PB Blaster, or a mix of Acetone/ATF fluid on the screws before removing them, they will come out very easy.
I have never found the need to use anti-seize on any of these fasteners .02

Catmandu2 said:
Not having my replacement SMC as yet,,, I decided to clean up and reassemble the top end components back into the original smc,,, essentially the push-rod, boot and clevis. With all the corruption that had accumulated I can see that the short actuating stroke could easily be impeded. Stopping power is going to push the piston down as far as it can,, much more than we can do by hand. But contamination at the intersection space between the push-rod and it's circular keeper plate,, and at the rounded nose of the push-rod where it contacts the cupped piston end, will prevent the piston from returning to it's full rest position. This would cause the rear brake to drag,, or even lock up. I believe that is what happened me. Anyway,, after a good cleaning,,, and filling the upper assembly with high temp synthetic brake grease,, it tested out fine on a 30 minute test ride ride, with lots of braking. Before putting it all back together, I did check the piston movement. It was about 1.5mm by hand,, and the same after full assembly. I could not check the full piston stroke,, as I had never opened up any of the hydraulics. Anyway,,, I have the whole winter to find a replacement for the old SMC. Maybe I will move on to coolant leaks, for a while,,,,, Cat'
Click to expand...

One page 17-28 of the 03-08 service manual, it warns you "Do not disassemble the secondary master cylinder push rod or the correct brake performance will not be obtained". While I have seen "piston kits" installed, you do so, by NOT ever removing the push rod.
I would suggest for the sake of safety, that the entire unit now be replaced since you don't know if you reassembled it back to factory specs.
.02
 
Catmandu2 said:
Putting my air box assembly back in place now. And I am wondering if using an anti-seize product (aluminium or copper based) on the JIS-phillips-head screws that secure the box to the throttle bodies,, is a good idea. They do get stuck,, probably due to the dissimilar materials,,, and I am replacing a couple that were in rough shape. The copper based anti-seize is for heat applications,, and is recommended for sparkplug threads. Anyone tried this,, or other products, with success ?? Cat'
Click to expand...

The shop removed mine the first time in 2009, maybe 2008; anyhow, with a JIS screw driver they come off cleanly twice more now. A regular phillips screw driver would tear them up. Get a JIS screw driver from Amazon and forget about anti-seize.
 
The best deal I have found for JIS driver set(s) is McMaster Carr.
IIRC a 3 piece set was about $25 dollars (Vessel)
 
I have been using the JIS screw driver that came in one of my Honda tool kit's (not sure which one it came from). A couple of the screws were messed up by a PO and/or his bike shop. This is not surprising,,, as I have replaced numerous abused fasteners on the bike. This is the 2nd time I have had them all out myself,, and I was surprised at how stiff they were to remove this time around. I snugged them up,,, but not extremely tight. I just want to avoid the difficulties that some have had,, noting that a couple of posters have switched to Allen-heads. Since I am sticking with the oem screws,, a JIS driver with a hex drive on the shaft to allow a small wrench assist to be used for dis assemblies. Cat'

Reginald said:
The shop removed mine the first time in 2009, maybe 2008; anyhow, with a JIS screw driver they come off cleanly twice more now. A regular phillips screw driver would tear them up. Get a JIS screw driver from Amazon and forget about anti-seize.
Click to expand...
 
Catmandu2 said:
I have been using the JIS screw driver that came in one of my Honda tool kit's (not sure which one it came from). A couple of the screws were messed up by a PO and/or his bike shop. This is not surprising,,, as I have replaced numerous abused fasteners on the bike. This is the 2nd time I have had them all out myself,, and I was surprised at how stiff they were to remove this time around. I snugged them up,,, but not extremely tight. I just want to avoid the difficulties that some have had,, noting that a couple of posters have switched to Allen-heads. Since I am sticking with the oem screws,, a JIS driver with a hex drive on the shaft to allow a small wrench assist to be used for dis assemblies. Cat'
Click to expand...

Motion Pro sells (2) JIS bits for about $5 bucks, and they also sell a T-Handle bit driver that comes with a couple JIS bits. The T-handle has (3) insert points, for reach, and for leverage. This is a simple must have tool for your box or bike tool kit.
Mine has a #5 Allen (for most fasteners) a #2 JIS bit for just about every screw on the bike, and a #6 allen for the SMC assembly. All you need is a 1/4 socket adaptor and some sockets and you can just about do anything you need to in an emergency.
 
Catmandu2 said:
I have been using the JIS screw driver that came in one of my Honda tool kit's (not sure which one it came from).
Click to expand...

You might have a good JIS screw driver. My experiences with tool kits provided by manufacturers has been poor to worse. Generally low bit stuff. Follow Larry's advice and get a decent driver.
 
A tire repair kit and a compressor get pulled out on the road occasionally but in nearly a quarter million miles on Hondas I can't really remember using the supplied tool kit at all. Good tools are at the house :)
 
That's my favorite one! The only downside is they work so well I have never had to use the impact.
 
While surveying the local tool counter this evening,,, I saw a socket driver that had an adjustable torque limiter built into the handle. That could be handy,, and the socket will accept any standard size driver bits,,, JIS and otherwise. It did not come with a JIS bit though. I will visit the competition tomorrow,,, Cat'

Igofar said:
That's my favorite one! The only downside is they work so well I have never had to use the impact.
Click to expand...
 
Working on my old 305 Scrambler I chewed up many a 'cheesehead' screw with Phillips screw drivers. I got one of those heavy impact drivers and things went a little better. But it still used Phillips bits.

It wasn't until being held hostage in the OCD garage that I found out about Vessel/JIS drivers. (Always wondered what that little dimple on the screw was for.)

I've got the 3-driver Vessel set and the Motion Pro T handle with three bits. Those and a 5mm T-Handle pretty much covers everything on the bike for me. I know who has anything else that might be needed. ;)
 
You must log in or register to reply here.
Back
Top Bottom