That rules that one out then. Are both the holes in the bottom of the reservoir clear?
[QUOTE=Don-Spada] That rules that one out then. Are both the holes in the bottom of the reservoir clear?
[/QUOTE] Funny you should ask that because in the m/c, one was clear, the other only partially drilled!!! There is only one hole in the reservoir. I decided against drilling through the second one in the m/c. I scratched at it (with a match stick)to make sure it wasn’t just blocked but it actually hadn’t been drilled all the way through. Maybe I should have but it worked ok before with one hole, bearing in mind that the splitting facility is taken care of by the separate splitter above the m/c, I figured it hadn’t been drilled out for that reason.gogoguzzi2013-06-18 11:18:41
I wouldn’t drill any holes in it! Especially not if it worked before
That was my thinking too. This all arises because though I was fixing something that wasn’t actually broken but thought it would be a good idea to replace 20 year old rubber brake hoses with new braided ones. Simple job - not.
Had a check on my spare M cylinder, and one goes through, the other is blanked off so must be correct
there must be an air leak …my bet would be the brake nipples… but it may be a faulty hose!!!
Let’s recap ~ when you say it won’t bleed, do you mean pedal won’t go hard? (oo-er matron) I don’t think you mean fluid won’t go through because of “drawn two litres of fluid through” My guess is there’s still lots of air in it that is just compressing and not being expelled. Haven’t put a new set of hoses on for some time but bet I had similar hassle when I did. Actually had a bit of bother last bleed session just recently. So also make sure MC piston is returning fully on release, if it doesn’t it won’t pick up more from the reservoir and will just keep going backwards and forwards with no resistance, guess how I know It was doing this latterly too, last time required an o/haul kit to fix it but think I got away with it this time by ‘exercising’ and freeing the piston. Maybe need to try Ken’s method with the syringe, by ‘blowing’ it back from the front caliper instead. Note fitting new pads beforehand doesn’t help, 'cause of the (unwanted) extra free play that that introduces into the proceedings. HTH
If this persists take off the mast cyl, caliper and hoses take them to a specialists.
Where abouts are you? Anyone local who could help out and take a look?
I am on the Kent/East Sussex boarder. Although I have refurbed the m/c, I am considering buying a new replacement. It is quite possible that although refurbed, the bore may be worn and therefore not working properly. Given my life could depend on it, £120 seems a small price to pay to eliminate once and for all, a faulty m/c.
I assume that m/c = master cylinder and not motorcycle or master of ceremonies?
Before splashing out a lot of dosh on a new master cylinder, why not start again from basicsCan you drain out the system completely, and get some air pushed through to see if the lines are clear. Maybe remove the lines and blow them through.I assume the splitter on the Targa is just a junction box with nothing special in it so you should be able to blow air in and out of all holes.Check the nipples are seating correctlyThen refill the system, back or forwards whichever way you prefer. Raising the calipers or Master cylinder is a good idea, let gravity help you.
I tested my master cylinder by connecting the rear calliper directly to it with a spare hose and test bled it
Mine proba turned out to be a blocked manifold
Do NOT drill thru’ the apparently blank hole, it will in fact have a tiny hole into the main bore. This hole controls the beginning of pumping/pressurisation but must be very small to prevent extrusion of the main pressure seal up into the reservoir area. The larger through hole allows fluid flow to/from the reservoir into the system behind the main pressure seal which collapses on the return stroke as the brake is bled.
There you go!
Sounds like my small hole is blocked then and it all now makes sense so thanks for that.
Good plan to test the master cylinder by connecting a single caliper to the master and see if you can make that work.
I have just spent all afternoon trying to bleed the front brake on my Convert and FAILED! I have tried the reverse syringe way. Tried the non reverse pipe thingy way. Got my caliper up in the air perched on tin cans, but I can’t get it fully bled. It is getting there - there is pressure there, but it is still springy. When I pump the lever with the nipple closed I am getting tiny bubbles in the master cylinder reservoir. I have been pumping for ages hoping that they will stop, but they keep on coming. They are tiny but it’s air none the less. I don’t know if it’s coming up the pipe or if there is a problem in the cylinder. I hate brakes - and I’ve still got the linked ones to do, I’m losing the will to live!
Tie the brake handle to the bars so fully on and leave for 24hrs and then re bleed!
jmee if you did the reverse bleed on the front brake and there is still air in it
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you are doing it wrong, which I doubt but it is a possibility air gettint in at the nipple
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the nipple is not sealed correctly, common problem clean the caliper at the bottom I use a small nylon test tube cleaner
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the hose is not sealed
Reverse bleeding done to spec pushes ALl the air out UP to the master cyl. The mastercyl could be faulty
Brakes are not that difficult
IF anyone has problems it HAS to be air getting in…STOP and figure out whet you fitted last