Manky Monkey Motors

Have been bleeding my rear brakes for the last 2 hours. Tried an eezi bleed kit,no success! Tried Toads method of removing the calipers and getting them as low as poss(in my case cant get the caliper bleed nipple below the master)No success! Have used 2 bottles of fluid! Air comes out of the bleed tube every 3 or 4 pumps of the pedal,but still havent got any sort of 'pedal' !
  Could air be being sucked in ,but fluid not leaking out? All joints are dry  and clean!
  Does the reverse bleed with a syringe work?
 Anyone know of any sealer that is effective?
  Going to strip the whole brake system down tomorrow and start again!

In what order are you bleeding things? I`d start with the master cylinder then the front caliper and finaly the rears. If it is just the rears that are playing up,open the nipples, jack the back end up, leave it a few hours then bleed it still in the air. If all connections are good you won`t be drawing air in.

Order= m/cyl union,front calipers,t pieces between m/cyl and rear . Longest run to rear ,shortest run to rear. The way I see it is that there must be air getting in somewhere,so will re do the whole system tamara.TBH I'm not happy with how some of the hard line runs look,but was leaving it to get it road tested . Think I'll take this opportunity to tidy up the whole thing.I'll use stiffer tube ,so that when I remove the lines they wont go out of shape before I re fit them on the last strip and build.

if nipples are not a good fit on threads they will draw air, try a smidge of plumbers tape on threads see if it improves...

Had another go ,but still no joy. Had a proper measure up today and am ordering all the proper stainless lines tamara,then I'll have a solid base to work on ,as at present ,its new ,but looks tatty.
 Ive been told to grease the nipple threads to prevent air getting in when bleeding.

I've never been able to bleed my Superdream or GT550 brakes succesfully - until I bungee them up and leave them overnight which seems to do the trick.

But bleeding the rear (Reliant) brakes on the trike, on the other hand, is easy!

This is where Im at so far............Replaced all copper washers on banjos ,stopped weeping from unions. Bled whole system (many times) still no pedal. Pump pedal a few times fluid in m/cyl goes down.release pedal,fluid comes back up in m/cyl.Close the brake balance valve .Instant solid pedal and front brakes work fine.All this seems to point to air in the rear part of the system,BUT,no amount of bleeding will get the air out(if it is in there!)Run out of fluid now ,so gotta get more . Ive also removed the balance valve from the system by bridging with a piece of pipe to see if its that! Seriously p****ed off ,and really cant be arsed anymore!

C`mon mate keep at it! How are you doing the bleeding process? Step by step, what are you doing?
You mention pumping the pedal so i assume the rear caliper pistons have moved out to position the pads against the discs?

Bled fronts,at nipple at headset . Bled at front calipers. bled at nipple connected to T about 9" from m/cyl. Bled furthest rear caliper,then nearest rear caliper.Air comes out ,then just fluid at each bleed point . Repeat process 3 times still nothing.
 TBH Ive tried so many ways ,Im now confused about what I have done!

Sorry mate, i wanna know how your bleeding, not what order. I take it you have help with it?
How is your bias valve set when you do the rears?

The bias valve is set full open when bleeding....open nipple 1/8 or 1/4 turn ,depress pedal,close nipple,raise pedal.etc etc . Another time I tried pushing fluid from the nipple to the m/cyl with a syringe,then bleeding as above. Ive also bought an eazi bleed kit ,but although I got fluid coming out the nipples ,I couldnt get a good seal on the m/cyl,so gave up on that one.the bias valve is puzzling me. I get a better pedal if the valve is say,half wound in ,the fronts lock on ,but the rear pistons dont move.

wherabouts are you rod????

I`ll state the obvious......ditch the valve. Well for now anyway, its gotta be time to start eliminating componants.

hi rod. what master cylinder are you using. is it new or second hand. when you press the peddle down is it a positive pressure of fluid coming out or a dribble. i had the same problem with mine tried everything. it turned out to be the master cylinder washers. fluid passing the 1st washer. pop the dust cover of a see if its damp

Ive ditched the valve,still no good!
  Im in Essex.
 m/cyl is new ,but am considering borrowing one to swop over temporarily.

yes mine was new as well. but old stock. peal the dust cover of the master cylinder and check if it damp

don't know if this helps, but we had a Moggy Minor in the garage for the last few weeks, the guys in the workshop could not get any sort of brake, it just went down to the floor.
Last week it was a little slack for MOTs so I went and had a look.
I used my hand and pushed the pedal up and down very slowly, not much at first, then after a while (About 2/3 Min's) I had a little pressure at the bottom of the stoke. I got one of the so called mechanics to open one nipple until the pedal went all the way down. I done this on the rest of the brakes and after about 1/2 hour had good brakes.
One thing you have to check is the the piston is coming all the way back, you can check this by looking at the fluid, when you start to put the pedal down, there should be a little squirt of fluid (Or air) coming out of the little hole.

Terry I'll check this ,but havent put the dust cover on yet ,and it all got a bit wet when The eezi bleed pissed out everywhere! Strange how the 'pedal' is there when locking off the rear brakes tho'.
  Cunningplan . Minors /A35's can be an arse with the brakes. I may give that a go later!

still no joy mate?
if you want to try my master cylinder pop over tommorrow.it would rule out another  component .

I would have thought that this problem, having been covered under various other parallel threads on this site would have gone away by now, but, as I have pointed out previously in those threads, it ain't Rocket science, and with the leaks you admit to having you will never maintain an air free system, so start again. Separate front and rear hydraulic systems using blanks, redo all joints, fill the system, front or rear as selected, and crack the bleed nipples at slave cylinders, allowing them to drain by gravity until the piping is full. Once done, and with no leaks or of course "passing" cylinders! you MUST then get a brake once the bleeds are closed, even without final bleeding to eliminate all final air bubbles....you MUST!! really. If you don't, then your system is poorly installed and drawing air on cylinder return strokes, definitely. Once half of the divided system works, move to the other half and do the same. and eventually, put it all together,leaving any bias valves out, at least for now! they can be problematic, give it a try this way......please....Morrag

Going off at a bit of a tangent, is your brake pedal pushing the pushrod all the way into the master cylinder?

2 thoughts;

If the fronts seem okay, can you close the bias valve and only 'work' on the rear brakes..?
(my nissan rears were a complete bugger to do, with such a long stretch from m/c to calipers)

If you are sure that there seems to be no air and its still not coming up to pressure, is the bore of the m/c big enough to power all the calipers/cylinders you are using ? (what front brakes have you)

Good luck...Bazza

OK guys .thanx for all the words of wisdom.A new day ,and a new set of ideas to try! Will be out there as soon as the shop opens to get more fluid!

ay up blokes i invested in one of them there vacuum brake bleeder it iz just the job got mine of evil bay realy easy to use hope the may help DB

Another waste of fluid! Took my 5/8" m/cyl off and replaced it with a  brand new 3/4" one borrowed from oldskoob.Bypassed the bias valve.Checked every joint for leaks. Bled out whole system . Still cant get a pedal.When I pump the pedal,I have brakes on all wheels,but a very spongy pedal.No more air coming out when I bleed them.I have 4 potcalipers on front ,Golfs on rear. Im absolutely out of ideas now,and just p****ed off bleeding the things!

 Hmmmm...now wheres that grinder..........................

Whats your phone number Rod? pm me.

pm sent...........

If you've got 2x 4pots on the front, then the m/c might not be moving enough fluid for the whole set-up. My mate Pirate had problems with just one 4pot (changed from a single pot) and got frustrated to hell, bleeding bleeding bleeding, and no pressure....He borrowed a modern bigger bore jap m/c off me, designed for 4/6 pots and it works great. (bugger still has it  ;D ) Is there an even bigger bore m/c you can try ???
Good luck...Bazza

I see where youre coming from and yeah there are larger bore cyls,but I doubt whether it is that. I just cant get any pressure on the brakes unless I pump them a lot.When I had the bias valve fitted ,if I closed it,I had perfect pedal on the fronts. So I would come to the conclusion a) there isnt enuf 'push' in the smaller bore m/cyl OR b),as TB and others have suggested, air in the rear lines/calipers. BUT Ive bled the s**t out of them!Going out fer anuver try now..................

Right this is where Im at....Removed and pluged off rear brake circuit at the T piece. Result = instant rock hard pedal for front brakes. Step two...removed/ plugged off front brake circuit at T piece.Replaced pipe to rear brakes. Bled out rear brakes again ,tapping the calipers to remove any trapped air.Result = as before ,no pedal!
 

Block the r/h rear and work just on the L/H side now.

Cool,You're getting there by elimination... With the front part blocked off, have you tried 'back bleeding' again?? Sounds like air stuck somewhere, just moving backwards and forwards but letting fluid past... This sounds just like my Nissan. We bled it backwards and forwards sooo many times till it began working properly. Can you remove the rear calipers still connected to the pipes and hold them much higher than the rest of the system (with something wedged between the pads) and then try again ?
You'll get there.....Bazza  ;)

Also, once you have the rear circuit sorted if it still doesnt have good pedal pressure, have you considered a double circuit m/c...one for the front and one for the rears in one unit..?
Bazza

Right ,now Ive blocked off the n/s rear and bled the hell out of the o/side. Tapping the caliper with nipple open produces bubbles in pipe ,but they could be coming from the thread round the nipple,cos its open! Alot of fluid coming thro' has millions of bubbles,turning the fluid almost white at times. Now run out of fluid yet again,(£12 today!)so before I do any more fluid Im going to go on a vw golf site and ask about this.

hoo bloody ray! its gettin there, someone nip round to Rods with more fluid quick  ;D.
VW site! just do what we discussed.

not doubting you TB! Just read on a vw site that calipers should be bled on the bench before fitting. How you do that I dont know! ;D
 I just dont understand where all this air is trapped! On the REDS website where I had them done,they say they test all calipers with air,BUT mine definitely had fluid in them.Strange!
 BTW Still havent got a brake pedal!

You bench bleed in a more or less the same way as you do on the vehicle. All your actualy doing is pre filling the caliper, still needs to be done when its fitted.

Not yet, but you will. You`d be surprised where that air can hide, those T pieces can be buggers for retaining the stuff!  ;)

Are you doing this by pumping the pedal or using an easibleed? Try the easibleed if you have not. It moves the fluid through the system smoothly and quickly taking the air with it. The small bubbles that make it look milky white are from the constant pumping of the pedal me thinks!

Also use a clean container to catch the fluid and reuse it whilst you are tring to get this sorted. Once you have worked out what is wrong and have pedal pressure then just flush the system through with the fresh stuff. ;)

Is there a photo of the trike and it's master cylinder etc?

i have been round to Rods and to be honest it has confused the hell out of me as well!!!!!!
how he has kept his sanity is a mystery also.
this problem seems so simple to cure , and probably is , but even component elimination doesnt seem to produce a result .
if all the joints are dry underl pressure where is the air coming from? as people have said there is only a small volume that can be in there in the first place. so where is it getting in? i dont know.
is there anyone local who has any fresh ideas who could pop round and help a very patient but frustrated man. i will personally buy a pint for the man who can sort this one out!!!!

A pint? I'll make that a full on p*ss up if anyone can sort it! ;D
 Byzmax,I dont like using the once used fluid ,cos of all the tiny air bubbles just compounding the probs!
 Next thing to try is completely eliminating the T's and running a pipe direct from m/cyl to caliper on one side.
 THERES ALWAYS THAT GRINDER.........................

Let it stand over night till the bubbles have gone  ;D Where are you based?

(http://www.rodschopshop.co.uk/photogallery/media/trike/IMG_1269%5B1%5D.jpg)
Best I can do at the moment.....You can just make out the T with the brake switch sticking up to the right of the battery.
(http://www.rodschopshop.co.uk/photogallery/media/trike/IMG_1268%5B1%5D.jpg)

Essex. Too far for you mate! ;)
 Theres gotta be another reason for this. Been on a vw site ,they reckon they dont have any trouble bleeding the same calipers ,altho they dont say if they are new ,or just doing brake pipe work on existing calipers.

Will pm ya

hi rod. how is the brake pipe connected to the master cylinder.ie banjo fittings or standard pipe fitting. also is that the brake pipe we can see running back from master cylinder to some sort of fitting . i can not see the pipe coming from master cylinder properly. we will get you there in the end.  [PUT THAT GRINDER DOWN]

PM replied Byzmax..........
The pipe between m/cyl and T is a male 'car' type fitting on each end. It is just lying there in the photo,unconnected.

Rod

Had a look at your build thread, in particular the pics in this post « Reply #176 on: October 26, 2009, 05:40:39 AM ».

I noticed that the caliper is oriented with the park brake lever to top, if your calipers are the same as the ex Manky green trike (see 
http://www.mankymonkeymotors.co.uk/forum/index.php?www ) then you will have a problem bleeding the system as the bleed nipple will be lower than the highest point in the fluid chamber of the caliper. 

The calipers on the green trike have the caliper oriented with the park brake lever to underside so nipple is at, or very near highest fluid point.

In the design of all hydraulic braking systems a bleed nipple should be at the highest point of fluid within the component.

Hope this helps.

snafu

Dont want to ask the obvious but is that caliper mounted so that the bleed nipple is upper most ?? I cant tell properly from the picture..
Bazza

LOL....the above post appeared while l was doing this  ;D

 ;D ;D ;D ;D ;D

Great minds and all that  ;)

I asked previously on here about orientation of the calipers.Didnt ask specifically about bleed nipple position.I'll go look to see if I can get it higher.I honestly didnt realise it was that critical!
 UPDATE.....Just been out there pulled one caliper off. If you look at page 74 of Andys build it shows the n/s caliper.Looks like he has a banjo bolt with bleed nipple. This would make the bleed nipple even higher on the caliper than the existing one.Im presuming that you then bleed it from both nipples then? Looks like I will have to swop n/s for off side calipers to get same orientation. BUT has Andy bled his system?
As you say Baz,its hard to tell the orientation in the pic ,but if you look at it square on ,by swopping n/s for o/s it could be higher.,but compared to Andys  it is def different at present.Gonna try this today (after buying MORE fluid!)
 Another thought....I wonder if it would be poss to leave my orientation but temporarily move the caliper into nipple uppermost position,bleed it and replace it? Wonder if this may lead to complications later on?

Petty of me i know but......http://www.mankymonkeymotors.co.uk/forum/index.php?topic=6615.0.

Hi guys. Sorry, haven't been following this thread as closely as I should've.
Yeah, I swapped my calipers over, nearside to offside & vice versa. Main reason was because it made the routing of the handbrake cables easier. That was mentioned in the original disc brake conversion article I wrote for 100% Biker magazine, which is reproduced here somewhere, (& needs a serious re-write cos some of it doesn't make a lot of sense).
I ran a small amount of fluid through the system on my current trike build, but have now got the front end disconnected again so I can work on the steering stops/yokes. A couple of the joints were weeping a little, but I should be able to cure that with the brake union sealant I suggested earlier in this thread. Yeah, I've used banjo bolts with integral bleed nipples on the calipers. They're made by Goodridge.
Although I haven't bled the current system through yet, it's exactly the same as my last trike, which was then sold as a rolling chassis to Ska Man, who built it back up again exactly the same & had no braking problems either. All I can suggest is taking the calipers off the trike one at a time & holding them as high as you can with the bleed nipples uppermost while you bleed them.
Don't lose heart Rod. I'm sure I'll face all sorts of problems with my build when I try to fire it up & run it. Tis the nature of the beast I'm afraid.  :P 

ROD SAID; "I wonder if it would be poss to leave my orientation but temporarily move the caliper into nipple uppermost position,bleed it and replace it? Wonder if this may lead to complications later on?"

This would be fine....but every time the system needs bleeding that would have to be done each time....
Sounds like you'll have this done soon  ;) I admire your persistance and patience..
Bazza

TB ...Yeah I did take note of your reply at the time ,but thought it looked high enough to be honest!
 Baz...Patience ..yes.
         Persistence..I shouldve been more vigilant at the outset!
        Cock up on my part..absolutely! :-[ :-[ :-[
 *bows to all forum members who have helped on this thread ,and also well spotted snafu and baz!* :-* :-*
 TBH I ve never built stuff completely from scratch .Have modified dozens of suspensions/brakes etc,but mainly only by using brakes etc from other models .therefore already set up ,so to speak!
 Not out of the woods yet! Gotta go experiment bleeding calipers in new positions!
 The money for the brake fluid is flowing out of my pockets as fast as the fluid is running out the bleed tube!! ;D Im now really begrudging going to spend money on more fluid! ;D
 
 *UPDATE***
 SWAPPED CALIPERS LEFT FOR RIGHT. MORE FLUID IN ...ABOUT 4 PUMPS AND I HAD A PEDAL ON BOTH REARS!
 Had Planet Rock on the radio as I did it ..song they were playing was apt....Yes..."Yours Is No Disgrace" !

 A re route of all rear plumbing ,and making up new pipes along axle should see this sorted by end of the evening.
 

do ya know i never noticed that!
dohh!!!!!
i feel like a prat for not twigging that one either ???
never mind alls well that ends well eh Rod

Hurrah!
So glad you didn't give up Rod! Now put that angle grinder away.  ;)

Well done mate. Roll on the christmas hols ;).

Im going for this w/end as a trial run. IF my new bolts arrive from pro bolt for the yokes.(got 2 missing).
 Just want to say thanks to everyone (you know who you are)for the moral support/help/phone calls etc . I honestly nearly did give up! So thanx again everyone.
 The power of this forum is amazing!

Top news that.  ;D

Great stuff  ;D  Looking forwards to more pics n things  ;)