Twinpot Brake upgrade on 78 Skunk

[Guest]

Salty, I'm rebuilding a set of ZG calipers. The parts fische shows that many seals are needed. By my count you should need 4 or 1 of each. Kawasaki says 8, 2 of each. What do you believe is correct? http://www.cheapcycleparts.com/oemparts/a/kaw/500b239af8700223e478c24e/front-brake

You need one each of 43049,43049-A, 43049-B and 43049-C per caliper. Two of them are seals and the other two are wipers.


Mark

 

[salty_monk]

It's been a while since I pulled a set apart. I think there is a sealing O ring inside the bore of each piston & a dust seal at the top of each piston.

I've not yet found a pair (especially of the RG ones as they tend to be newer) that need new seals.

New rubber bits related to the sliding assembly caused by brake fluid contamination swell or damage.

If you look at one of the K&L kits (which I wouldn't necessarily recommend I've read of mixed results with them) it shows the same as I remember...

http://www.ebay.com/itm/KAWASAKI-NE...ash=item2a67948d6c:g:-54AAOSwInxXMjZW&vxp=mtr

 

[limeex2]

Thanks! Makes sense but doesn't make sense...Here's my issue. Good master, steel lines, rebuilt(not by me) calipers with K&L parts. With bike sitting(or driving)Initial lever pull travels what I feel is excessive and builds pressure as it goes towards bar, still braking well other than initial long travel. 2 quick stabs on lever and it is 2 finger great braking. The guys on the ZRX forum are fanatics about brakes and the consensus is caliper seals are rolling causing excess piston movement before sealing up and to rebuild with OEM and NEVER use aftermarket stuff for brakes. Thoughts before I spend time and $$$ ? Where is a good place for brake seal grease?

 

[Guest]

Here's my issue. Good master, steel lines, rebuilt(not by me) calipers with K&L parts. With bike sitting(or driving)Initial lever pull travels what I feel is excessive and builds pressure as it goes towards bar, still braking well other than initial long travel.

I have the same calipers (off a ZX6, tho) and also have very long lever travel before they bite. I rebuilt mine with OEM Kawasaki parts before installing them. Pumping the lever makes very little difference, it doesn't come back like after you have changed pads and have to push the pistons back out. It simply takes quite a bit of lever travel to get them engaged. I have just learned to live with it, the lever never comes back to the bar and won't trap fingers so I am not too worried overall. I do plan to pull my MC apart this winter and see what condition the stack is in just as a precaution, but there isn't anything that makes me think it isn't working correctly.


Mark

 

[salty_monk]

We did have one set on here years ago that had issues with the bleed valves not sealing properly.. that was causing something like the issue you are experiencing, got to be worth a check.

Different M/C's will feel different. If in doubt pick up an EX650 one & try it. They are newer & often available for $20-$30 on Ebay.

 

[Nickolarge]

I had a spare pair of CBR 900 296mm discs that intended to keep but a shortage of Christmas cash has made me put them on eBay.

I've started them at ?20 in a 7 day auction ending next Sunday 18 Dec. Free postage to the UK.


http://www.ebay.co.uk/itm/-/182385641494?

 

[Inazumarob]

Hi Guys, new to forum and have been following brake thread.
I just wanted to let you know that I managed to vastly upgrade the std brakes on my friends GSXR 1100 H (87 MODEL SLABSIDE) with the std 3 spoke wheels. I tried various ways, and eventually put a Nissin 17mm Master Cylinder off a Yamaha XJR 1200/1300/FZR 1000 on to the bike. All other things were std, apart from braided hoses and this greatly improved the performance by at least 50% with no feel or travel issues. The only thing I had to change was the Banjo Bolt, as the cylinder has different thread.
Regards Rob GSX 1100ET

 

[carusoat]

Salty,

I'm thinking about upgrading the brakes on my '78 skunk restoration. Could you tell me if these calipers and rotors will work?

http://www.ebay.com/itm/401205984388?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

http://www.ebay.com/itm/192033696479?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

I think they're right but I just want to double check. If I go with these, do you have any kits available that aren't black?

thanks!

 

[Chuck78]

Yup, those appear to be the ones. I didn't know those calipers came on a 91 gsx1100g katana, however. Do the look identical to the GS500 and ninja 250 calipers? Short on time or else I'd compare myself. Pretty certain those will work though. They look to be identical as far as I can tell.

 

[carusoat]

They look the same as the ninja calipers to me. Somewhere in this thread Salty listed a bunch of bikes the twin pots come on and the gsx1100g was one.

 

[salty_monk]

Calipers are right.... The rotors might be a bigger dia. The RR came with bigger dia some years.

 

[carusoat]

I ended up going with a different set of rotors off a 93/94 900rr. They measure 296 and have a different hole pattern than yours. I was wondering if you had any of your bracket kits available?

 

[salty_monk]

Yes I have some. I can get you some out over this next week no problem. I'll PM you.

 

[salty_monk]

I got some more bracket kits for anyone that is in need...

 

[erickson_ron]

I noticed that my left caliper sits 1/4 or so higher from axle then right side. Pad is too high. What am I missing?

 

[salty_monk]

Let's have a side on pic too if you can. I would say your left leg is off a single brake model and the other one is off a dual brake model.

 

[Chuck78]

Yes, what Dan said, & measure from center of axle to center of lower caliper mounting bolt on each fork slider. The 2 measurements should be the exact same. If what Dan says is the problem, one side would be 10mm further than the other (half of the difference between 275mm & 295mm OEM dual disc vs dingle disc brakes).

Measure both rotors to make sure they are identical. They should be, but some Honda models with ABS have one rotor that works for us and one that wont. The difference should not be in the diameter in that case as far as I have seen, but in the offset of the rotor.

 

[erickson_ron]

Yes it appears that in this bike's previous life someone fitted a single disc lower on the left. It is a small enough difference that I didn't pick up on it until finishing the brakes. Amazing the demons you will find hiding in old bikes. Thanks all and if you have a spare GS1000E lower left leg I am in the market.

 

[bobtail84]

Just a quick up date..

After I completed the twinpot upgrade I was never 100% happy with the feel of the brake lever.

So after a little bit of investigation I decided to use the master cylinder from a 96 Suzuki Bandit GSF 600 which cost me ?25.00 from eBay which is about the same in $ at the moment.

My main reasoning was the availability of the initial M/C, spare and service parts. The M/C also is a very good fit on the bars with regards to the switch gear and throttle cables and it also is very aesthetically pleasing meaning it looks like it should be there.

The GSF M/C has the mounts for the wing mirrors, again this was what I was looking for.

After a strip down and clean with a change of rubbers the whole conversion took all of half an hour including re-bleeding the brakes.

The end result is what I was trying to achieve with the original but didn't. The brake feel has gone from OK to absolutely spot on with a true 2 finger breaking with low effort for maximum effect and feel.

 

[Guest]

That's great, detailed info for people. Great post.