bleeding brakes

[wab]

Hello again i have 2 probs that i need some ideas for but i will do 2 seperate posts.
Firstly i junked the medieval front brake hose system on my 88 ta this morning and fitted a shiny new goodridge version...lovely.
Problem is even after hours of pumping the lever the traditional way, there is no pressure in the system, like theres an airlock. Drained the cylinder,it was abit cruddy but nothing sinister,and tried several other tricks but nothing works. Tried both bleed nipples but couldnt figure out why the cylinder requires a bleed nipple??
The haynes manual recommends a vacuum operated brake bleeder but i wondered if anyones suffered the same probs/knows any tricks/where the hell you get a vacuum bleeder from.AAAAAAAAAAAAAHHHHHHHHHH!!!
Cheers
Billy

[Cyborg]

I bled mine in the same manner as a car with the same non-return valved rubber tube. Mine is the twin disc version and I had no problems after fitting the braided hoses and bleeding the system.

[YEN_POWELL]

To fill the brake line, connect car type non return bleeding tube to caliper nipple

1/ Open bleed valve on caliper
2/ Apply brake
3/ Keeping brake applied close the bleed nipple
4/ Quickly release brake lever

When fluid (eventually when you feel old and weary after doing the above lots of times) starts coming out of the bleed tube attached to the nipple, bleed as below

1/ Hold brake lever
2/ Open and close the bleed nipple
3/ Release brake lever

Repeat for other side if doing the front calipers.

[wab]

this is the thing though yen all those points you so kindly pointed out were tried over and over for several hours but the fluid wouldnt get past the cylinder so didnt get a chance to fill the line itself.
Took the line off and tried just bleeding the cylinder direct but theres no pressure what so ever when you pull the lever in, like the plunger isnt working.But nothing apart from the line has been touched so why would it stop working.
So i wonder if the vacuum bleeder would help draw the fluid out and down through the line??

[harrisphil]

if the fluid is not getting past the master cylinder it sounds like the piston is stuck in the closed position
Remove the master cylinder banjo bolt and push the piston back towards the brake lever using a small screwdriver
using the screwdriver and the brake lever you should be able to feel the piston move
flush out the master cylinder with clean fluid and bleed as normall
as a final flourishpull the brake lever back towards the bars and tie in place using an old inertube or elastic cord in the morning all the air will have rissen to the top and you will have brakes

[ger]

Hi there,

Changed to stainless on my TA in the summer. Bleeding was a complete PIA, just as your are experiencing. I had a Mityvac vacuum pump lying around from a previous bad bleeding experience on my little Hotrod. Very fiddly but got there in the end.....

http://cgi.ebay.co.uk/Mityvac-One-Ma...QQcmdZViewItem


cheers
Gerry

[wab]

Ahh Gerry
You are my saviour, i was beginning to think i had messed something up.
Thankyou for your message and for the very nice link to the tool on ebay, thats a good price.
Im so glad thats the answer to my pig of a weekend so im off to purchase myself one of those beauties!!
Cheers

Billy

[mal]

Just a thought, would it be possible to bleed the brakes using a medical syringe, open the caliper bleed valve, connect a tube from a syringe to the nipple& carefully inject a syringe full of brake fluid back to the master cylinder, you would have make sure you don't blow the fluid everywhere would it work? possibly, worth a try, you would obviously need a reasonable size of syringe i presume you would get one in a Chemist shop

[icenian]

I've changed brake lines twice on the Africa Twin.

The first time it took about two hours. The second time round I had the Mityvac pump and I was all finished in about 10 minutes! Unless you're really skint, just buy the Mityvac, you'll be so glad you did. Even "regular" brake bleeding is quicker and easier.

[Steve T]

I use a catering syringe thats used for icing cakes (just done front & rear on my '91 TA) . I draw the fluid down to the caliper from resevoir but am mindful not to put too much vacum on the system in case seals give in. At same time I operate the brake lever which keeps things moving nicely.

Just the ramblings of an ageing teenager - honest.

TTFN,

SteveT