I'm having trouble successfully bleeding the brakes on my Harley Ferguson...I can't seem to fully expel the air from the system....Particularly so with the rear one.
Disc brakes are a bit of a 'black art' to me as I've had very few bikes with them fitted over the years and never had to mess about with them, though the principle of the hydraulics is simple enough......
I am told a vacuum type bleeder makes the whole procedure easy....
Before I rush out and buy one, does anyone have experience of these...and if they are to be recommended can anyone suggest a particular make (or supplier)?....Ian

email (option): ian@wright52.plus.com

Hi Ian
I have a Draper universal brake bleeding kit, its still in the box, I took one look at it and thought back to the milk bottle and rubber tube, but anyway the picture on the box shows it being used on a motorbike, so if you would like to have a go with it, I will get it down to you

I've got a Draper one too. I got it as a present a couple of Christmases ago, but I've never used it and like Colin, I just keep using my old mayonnaise jar with the rubber pipe in the lid. Not much help Ian, sorry.

Ian, I have had no experience with vacuum bleeders as I have always been too tight to buy one.

However, the front brakes on my Kwacka are a complete pain in the arse and I eventually found that removing the calipers one by one and using a piece of ply as a pseudo disk allows me to have the bleed hole at the absolute upper position and it bleeds very easily.

On my Buell I found that a persistent slightly spongy front 'lever' was cured by pumping up the lever very firmly and then using a tie-wrap to hold it on, turn the bars to left lock to put the master cylinder in an elevated position and leave overnight.
Release it next morning and it results in a magical firm 'lever'. That was a tip from one of the forums and it definitely works for me.

Not having attempted a Sportster rear I'm not sure about the location of the bleed hole but is it possible you are getting a very small amount of air trapped because of the orientation of the caliper assembly?

The one thing that will make life a lot harder is if you allow the fluid level to get low enough to suck air into the master cylinder piston but if you do it just takes a little more pumping and the overnight trick will catch the little air bubbles nicely.
I'm also assuming that you are trying to get back to a better pedal feel than where you are now as the HD / Buell rear brakes are well known as being pretty 'wooden' in standard trim?

BTW, I gave up on the standard brake pads that HD supplied for my Buell and settled on SBS Sintered Bronze front and rear. I've been through a few sets now and have done over 100,000km on that Buell and swear by those pads.

email (option): rays54@hotmail.com

Hi Colin...If it's a vacuum bleeder I'll have a go...and if it all works nicely I'm sure we can come to some arrangement...
Mail me to sort out a day for a pleasant ride across the moors and a cup of tea at Base Workshops..Ian

Ray..Yes, I've been told about holding the lever back with a cable tie so I might try that with the front one which is the better of the two anyway..
The rear one isn't one that can be removed very easily as the torque arm fits over the rear wheel spindle so the back wheel has to come out (or at least have the spindle partially withdrawn)
Caliper and reservoir are virtually level with each other as well hieghtwise..

I have done a lot of work on the bike which includes the fitting of new discs, one new caliper and one very low mileage caliper along with braided hoses, so it's just a matter of getting it all functioning again....I've also changed the pads for after market ones...Ian

email (option): ian@wright52.plus.com

I once borrowed something that put pressure on the system from a spare wheel to bleed a Series Land-Rover and that helped a bit (not a lot as those front drums had the feed at the top and bleed nipples at the bottom of the brake plate). It means modifying a filler cap though. Ramps to raise the front helped too. Can you hang the Harley up by one wheel ?

The cheap systems with a valve don't work. I bleed the Commando by very carefully only opening the nipple as the lever starts to move and shut it off every stroke...the theory of simply exiting the tube into fluid doesn't seem to work.

Overnight can help (I use a bit of old inner tube round the lever). The Commando front is a lot easier than the rear, especially since I fitted a master cylinder with no brake light switch. (hydraulic switches are a favourite place for air to hang up).

It goes without saying of course that any tiny amount of dirt in the master cylinder can block the fluid return and stop air from coming back to the top.

Ian, Harley master cylinders always get an air lock around the top banjo bolt, try cracking that off a few times and it dosen't matter if it spills everywhere as its only DOT 5 and won't hurt the paint

email (option): Davmax@ntlworld.com

Hi Lincoln Bill, is yours a Draper Expert Number 71205, only I seem to have misplaced the paper work on how to use it, if it is any good for Ians problem I was going to take to Base Workshops in Bere Alston

Try googling Mityvac, these are the ones that the motor trade tend to use, they do a plastic and a metal version, id go for the metal one, they last for years, you can buy spares for them and a lot of accessories to use them for even testing crank seals on two strokes. It appears if you buy them from the company themselves they are more expensive than if you get them from the ebay or Amazon. I've had mine for years, using it a lot and it still works perfectly. I've seen other mechanics using cheaper versions of them and they don't last too well.
Dave

email (option): davmax@ntlworld.com

Ian, another thing, are you using the correct pads in there? There were two versions of the caliper, one is from 1999 up to 2002 and then there were the 2002 and up , they look identical but the 2002 and up ones are thicker as I think they found that the pads were too good to replace on the first service, but didn't last until the second service so they altered the caliper in 2002 to take a thicker pad that would last. The Sintered pads are very good I use the EBC HH type but they do tend to wear the discs a bit but the pads last more than two services, I've done nearly 7500 miles on mine and they are only just getting thin, I'd be on my second set of the standard pads by now. I'm just telling you as I'm not sure what year your bike is. Harley master cylinders are renowned for getting the air lock at the top and sometimes even the Mityvac dosen't get rid of it.

email (option): davmax@ntlworld.com

Hi Ian,

Maybe I will "teach" the obvious, but I worked for Harley some 25 years ago, and that's how we did it:

One guy was pressing the lever, and another guy with a spanner/key slightly released the nipple at the rear brake.
the lever was losing height as the fluid squirt, but kept being pressed, and the guy at the wheel secured the nipple again.
(I am talking about release and secure of about 1/4 of a turn or so)

Then the guy at the lever "pumped" it 2-3 times to gain height again, and the nipple at the wheel released again.

We did it few times until we were satisfied that no more air bubbles are going out with the fluid,
and that the lever was firm and high. (not a long travel to the stop point)

The customer never returned to complain, and we used to wonder:
Either the work was good and the bike did brake,
Or it did not brake and there is no customer who can complain..


Cheers,
Noam.

BTW,

There is a development regarding your bearing.
I have one for you, brand new, British, no box, long story.

I will mail you and will update your bearing thread sometime later.
(It is Saturday and we are going to barbeque, the Israeli sport..LOL)

email (option): noam10@gmail.com

Hello all
Have you tried back bleeding it
Buy a new small steel oil can and a length of hose fill can with new fluid attach hose to bleed nipple open nipple and pump fluid back through system this works on l r disco clutches which sometimes are awkward to say the least

Thanks for all the constructive suggestions....With that lot I guess I'll be successful....Ian

email (option): ian@wright52.plus.com