Rebuild brake hydraulics as preventative maintenance? And what about the carbs?

I have a 85 R80 with dual Brembo brakes. I have no idea if the seals etc. are original or not. At this point they work well and don't leak. Is there any value in doing a rebuild as preventative maintenance? I read a couple of the British classic bike mags and is seems like whenever they pull old hydraulic brakes apart they are pretty ugly inside. Waddya all think?

I'm in the same situation with the carbs. Everything works fine, but I've always assumed that things generally do until they suddenly crap out? Any wisdom on this?

My thoughts...brakes, probably just doing yearly (or so) bleeding should be acceptable. That pushes the water out which is really what hurts the inside of the master cylinder. I didn't do the yearly bleeding and as a result had the internal seal get torn and thus no brakes. After the new kit, and lots of work honing the internal bore, things are back to feeling great again. I wish I had done better at bleeding...note to self.

As for carbs, I tend to monitor performance, namely how it starts, gas mileage, general feel running down the road. As long as all that is within range, I leave things alone. Easy enough I suppose to pull the float bowls and inspect for debris and/or water. Beyond that, if it ain't broke...

At that age, it might be worthwhile to replace the flexible brake hoses with a Speigler upgrade. This is a case of not wanting to suddenly crap out... I don't know what the original flex lines were, but if they are like the rest of their older lines, consider this.

Possibly the needles in the carbs are a bit worn, and the diaphragms may be getting limp. This wear is very gradual, but if it's happening, you'll notice an improvement after a simple R&R.

Thanks. When I got the bike the brakes weren't too potent so I replaced the pads and rotors with floating rotors and HH pads. I also removed the convoluted plumbing (it was originally an RT) and replaces it with a much shorted run of braided hose (Speigler, I think).

If you don't know whether the brakes have been treated to new fluid regularly over the course of the bikes life, it couldn't hurt to change the seals. Do not buy a new caliper piston until you've dismantled and examined it as they are expensive. Brake component deterioration is time and maintenance dependent, not mileage dependent. I don't know whether the same is true of the carbs.

It is the one way to be SURE that everything is right with an old bike. I've seen debris from decomposing hose internals in the cylinders and other junk. The rubber seals surely have a service life. Here is a rear caliper from my R1150 after 10 years of service...



Same caliper after tear down, clean-up, paint, proper lube, and new seals. Which would you have more confidence in?



Fronts from that bike disassembled...



Cleaned with new seals, lubed with Red Rubber Grease...



Finished up with new pads, etc...



Would it keep working if I didn't do all that? Maybe. But I don't like "maybe" for brakes. This way I have good confidence that the second decade will be as trouble-free as the first decade. Yamaha service manuals say to do it every four years. That seems excessive, but every decade does not (to me). BMW service manuals say not to split the caliper halves, and to enforce that, they do not offer the two small o-rings between the halves as service parts. I ended up locating them as repair parts from Kawasaki for a Brembo-equipped Kawasaki model (I forget which one).

I did this on a 92RS that I bought with only 15K miles on it. Precautionary, but I feel much better about it now and 40K miles later it has been 100%.

Ultrasonic tank the components...



New seals with Red Rubber Grease...



Piston and seal installed...



New crossover o-rings...



Finished rebuild...



Reinstalled and bled with new brake fluid and hoses...

+2 on the use of red grease for the rebuild. It makes the job much easier.

ccolwell said:

+2 on the use of red grease for the rebuild. It makes the job much easier.

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I think additional information is critical here. I have several different red greases and none of them would be suitable on a brake caliper seal.

Please be as specific as possible as to what red grease you are recommending for use inside brake calipers.

PGlaves said:

I think additional information is critical here. I have several different red greases and none of them would be suitable on a brake caliper seal.

Please be as specific as possible as to what red grease you are recommending for use inside brake calipers.

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Some info here...

http://www.redrubbergrease.com

A "How to" specific to brake calipers...

http://www.redrubbergrease.com/tips-how-to-brake-caliper-failure-repair-with-rebuild-kit.html

The product I use is by Millers...

I love the smell of Red Rubber Grease in the morning! I've been advocating it's use for years since I heard about it from a Coast Guard buddy who gave me a sample to try on my brakes. I now use it for most O Rings I install. My understanding is this stuff is a British Navy invention and was used on ship seals for many years and still used by their Navy (and Canada's) to this day. It not only lubes but preserves the rubber. It is an organic substance; not petroleum based but rather vegetable based and was designed specifically for use on all hydraulic and pressure seals on Navy ships. You can work with this stuff bare handed all day; it won't hurt you although it will soften your hands a bit.

+1 on the Red Rubber Grease, only drawback is when you buy an available quantity you end up with enough of it to last for thousands of brake jobs, at least for the home mechanic.

Mine was made by Castrol.

jagarra said:

+1 on the Red Rubber Grease, only drawback is when you buy an available quantity you end up with enough of it to last for thousands of brake jobs, at least for the home mechanic.

Mine was made by Castrol.

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You can buy Castrol (good stuff) and several other brands online in small quantites. Stuff ships from all over the world including USA. Some examples here: https://tinyurl.com/y4gbm2yp

One caveat is that larger quantities won't ship overseas. I think this is due to air shipment restrictions. A friend bought some of the small containers from Bulgaria which were OK to ship to Canada.

Everyone should bookmark this page for future use!

https://store.bevelheaven.com/Brake-Related-Parts/