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1978 T140E problems???

4K views 8 replies 6 participants last post by  380Viking 
#1 ·
Hello all. Having several problems with my '78 Bonneville and need some help. The motorcycle is not used a lot, has 7,000 miles on it. Having trouble with the rear brakes, for the longest time they would hang up, that is to say that once they were applied, they would almost lock up, you could hardly even push the motorcycle at all because the rear tire was almost locked up. Well, got tired of that I removed the rear caliper to check things out. Found that the pads are pretty thin, no more than 1/16 of an inch thick for one thing. Anyone know about how thick new ones should be? Also while working the two caliper pistons in and out to free them up, found that they would only move when I released the bleeder nut. Did that several times and reinstalled everything. Now I cannot get the system to bleed properly. I've bled brakes numerous times, so I doing it properly and I've used at least 8 or so ounces of DOT 3 and still no good results. The brakes will pump-up and I can bleed them as they should and within a second or so, the pedal bottoms out. Have done this at least 30 times or so to no avail. I'm thinking I have more than air-in-the-line problems. Maybe the pads are too thin and the pistons are moving out too far??? Oh yeah, almost forgot, when the pedal is pressed, I hear what sounds like a brief air hissing sound until the pedal bottoms out. Any advice out there other than replacing the pads ??? Thanks
 
#2 ·
Welcome to the board, MGB.

You'll have better luck with your question if you head on over to the Classics and Vintage section. That section is for the Meridan bikes. This section is for the owners of Hinckley bikes to complain about bad suspension (true), uncomfortable seats (also true) and lack of power (true as well).

By the way, if you actually have an MGB and have pics of it, posting some would be a good idea. :)
 
#5 ·
Hi,

I also have an MGB and also a Bonneville T140E (1979).
I had a problem similar to yours and here is what I did :
dismantled the caliper, cleaned completely (with brake fluid), replaced the Orings AND nothing changed. (The pads would release very slowly after rear brake use)!

I changed the oil line and that was it, problem solved!!!
It was blocked due to age and would let a very small amount of brake fluid return.

Hope this helps
 
#6 ·
http://www.triumphrat.net/classic-vintage-and-veteran/126735-dot-5-brake-fluid-in-t140.html

http://www.triumphrat.net/classic-vintage-and-veteran/153790-need-tips-on-bleeding-76-t140-rear-brake.html


See links to other parts of this forum on this subject - what I would add is that in order to get the best results when bleeding the rear Brake - I would take the Caliper off and turn it up to get the Highest point for the Bleed Nipple as your caliper is underslung ,to assist in removing any trapped air in the system - I have also attached an article on Lockheed brakes should you need to strip down the ineternals and re-build .
Let us know how you get on .
:)
 

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#7 ·
Thanks to all for the replies. Still working with the brake bleeding problem. Hey 75JAZZ, I'm in Blythewood, just a few miles north of Columbia not far from I77. Yes, any info. on local places to get parts opinions would be helpful. Thanks
 
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