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| Jackson hydraulic handbrake help needed https://www.ausmini.com/forums/viewtopic.php?f=5&t=47477 |
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| Author: | mickmini [ Tue Nov 11, 2008 5:51 pm ] |
| Post subject: | Jackson hydraulic handbrake help needed |
Fitted the Arthur Jackson hydraulic handbrake. Setup is Cooper S master, Cooper S front calipers, Tilton adjustable bleed valve in front of handbrake input, handbrake input in rear hole, handbrake output from front hole, T piece, rear wheels. Everything is new, master, calipers, bias valve, rear cylinders, rear drums, cable handbrake adjuster wedges. Everything that could possibly cause a problem has been renewed. The system has been bled using a power bleeder system and manually. Before i fitted the new bias valve and hydraulic handbrake the pedal got hard after about an inch or so of travel. Now it goes down to about 1.5 inches off the floor to get hard. If i pull the handbrake on, the pedal goes hard almost immediately. if i push on the pedal then pull the handbrake on, i can feel the pedal getting a little back pressure. pulling the handbrake on locks the rear wheels no problem. I don't like having such a low pedal as it gives me no confidence, and makes heel-toe gear changes difficult. Has anyone else had a low pedal when fitting one of these? What am I missing???? cheers michael |
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| Author: | gafmo [ Tue Nov 11, 2008 6:07 pm ] |
| Post subject: | |
adjust the rear brakes a little more. Did you replace the drums |
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| Author: | albino235 [ Wed Nov 12, 2008 7:09 am ] |
| Post subject: | |
Quote: What am I missing????
Your missing pictures, some of us would like to see pictures of this handbrake kit and install... And to answer your question did the kit come with some sort of check valve so that it only pressurizes the rear lines? or is that what this "Tilton adjustable bleed valve" is? If that is some sort of adjustable check valve, maybe it needs adjusting... Cheers, Alex |
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| Author: | Morris 1100 [ Wed Nov 12, 2008 4:07 pm ] |
| Post subject: | |
The hydraulic handbrake acts as a non-return valve. It is a master cylinder that gets fed by the main master cylinder. When you use the foot brake the fluid to the rear flows straight through the handbrake master cylinder to the rear cylinders. When you use the handbrake the piston in the handbrake master cylinder closes the feed port and pressurises the rear cylinders. There should be nothing in there to cause a loss of pedal. |
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| Author: | mickmini [ Wed Nov 12, 2008 7:39 pm ] |
| Post subject: | |
Morris 1100 wrote: The hydraulic handbrake acts as a non-return valve. It is a master cylinder that gets fed by the main master cylinder.
When you use the foot brake the fluid to the rear flows straight through the handbrake master cylinder to the rear cylinders. When you use the handbrake the piston in the handbrake master cylinder closes the feed port and pressurises the rear cylinders. There should be nothing in there to cause a loss of pedal. yeah i know all that, which is why it is giving me the S$%ts that the pedal is so damn low. and yes Jim the drums are new (read original post) anyone else with any bright ideas? cheers michael |
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| Author: | sports850 [ Wed Nov 12, 2008 10:13 pm ] |
| Post subject: | |
Now bearing in mind I have no knowledge of the hydraulic handbrakes whatsoever , is it possible to try and bleed the front brakes with the handbrake "on" (presumably locking off the rear brake system so you are only pressurising the front) to see if that makes any difference (i.e, the problem is somehow in the front and just happened to happen at the same time as you fitted the hydraulic handbrake ?) . If it doesn't change anything then look to the rear (can you bleed the rears using the handbrake only ?) by whatever means you can ? I'd be looking for air trapped in a bend in a pipe somewhere that has escaped the two bleeding techniques you've already tried ??? |
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| Author: | TheMiniMan [ Thu Nov 13, 2008 9:44 am ] |
| Post subject: | |
My Question would be related to how long the "throw" is in the ti\lton limiting valve? if it travels a fair way then there is your problem if you look at a mini limiting valve, it hardly travels a few mms,,, then it locks up, so very little pedal travel occurs with this minimal amount of limit valve piston travel,,, so if the Tilton has quite a long bore & the piston moves quite a long way then i`d be isolating that valve (for the monet as a test) to see if your pedal recovers just a thought as i can`t see the valve, or the car, or the rest of the system if you know what i mean |
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| Author: | doogie [ Thu Nov 13, 2008 11:01 am ] |
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After reading your story Mick, my Cooper S with a i say Arthur handbrake gives the same pedal feel, so does Scrapper which has the same set up too, you just get used to it. Doogie |
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| Author: | simon k [ Thu Nov 13, 2008 12:13 pm ] |
| Post subject: | |
it's just a matter of too much capacity in the system - the master cylinder pushes a constant amount of fluid, adding more pistons to move means less pressure at the wheel cylinders so basically what Matt said I retained the standard pressure limiting valve on the rear subframe, and lost a tiny bit of pedal - maybe half an inch |
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| Author: | mickmini [ Mon Nov 17, 2008 8:07 am ] |
| Post subject: | |
2 S's & a clubman wrote: After reading your story Mick, my Cooper S with a i say Arthur handbrake gives the same pedal feel, so does Scrapper which has the same set up too, you just get used to it.
Doogie Doogie you mean the same feel as without the hydraulic handbrake? or same as i described above? cheers michael |
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| Author: | doogie [ Mon Nov 17, 2008 8:19 am ] |
| Post subject: | |
mickmini wrote: 2 S's & a clubman wrote: After reading your story Mick, my Cooper S with a i say Arthur handbrake gives the same pedal feel, so does Scrapper which has the same set up too, you just get used to it. Doogie Doogie you mean the same feel as without the hydraulic handbrake? or same as i described above? cheers michael Same set up, less the bais valve. Doogie |
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| Author: | smiling_simon [ Mon Nov 17, 2008 12:57 pm ] |
| Post subject: | re: brake issues |
simon k wrote: it's just a matter of too much capacity in the system - the master cylinder pushes a constant amount of fluid, adding more pistons to move means less pressure at the wheel cylinders
This is true but needs clarification: The pressure in the system will be less for the same amount of pedal effort (your foot) as you have changed the dynamics of the braking system. Same thing happened when I put 4 pots on the front end instead of 2 pots. The brake pedal goes down to the same distance as you've quoted now. You're right, it screws up your heel and toe action and takes confidence away from you. Sounds like your limiter is giving too much pressure to the rears (taking that pressure away from the fronts), or that you need to change your master cylinder from lower bore to a higher bore to decrease pedal travel. |
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| Author: | mickmini [ Tue Nov 18, 2008 6:57 am ] |
| Post subject: | |
2 S's & a clubman wrote: mickmini wrote: 2 S's & a clubman wrote: After reading your story Mick, my Cooper S with a i say Arthur handbrake gives the same pedal feel, so does Scrapper which has the same set up too, you just get used to it. Doogie Doogie you mean the same feel as without the hydraulic handbrake? or same as i described above? cheers michael Same set up, less the bais valve. Doogie but what does the pedal in the cooper S and scrapper feel like before and after fitting the handbrake???????????? |
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| Author: | mickmini [ Tue Nov 18, 2008 7:19 am ] |
| Post subject: | Re: re: brake issues |
TheMiniMan wrote: if you look at a mini limiting valve, it hardly travels a few mms,,, then it locks up, so very little pedal travel occurs with this minimal amount of limit valve piston travel,,, so if the Tilton has quite a long bore & the piston moves quite a long way then i`d be isolating that valve (for the monet as a test) to see if your pedal recovers smiling_simon wrote: The pressure in the system will be less for the same amount of pedal effort (your foot) as you have changed the dynamics of the braking system. Same thing happened when I put 4 pots on the front end instead of 2 pots. The brake pedal goes down to the same distance as you've quoted now. You're right, it screws up your heel and toe action and takes confidence away from you.
Sounds like your limiter is giving too much pressure to the rears (taking that pressure away from the fronts), or that you need to change your master cylinder from lower bore to a higher bore to decrease pedal travel. to be clear, it had cooper s discs and 2 spot calipers before, a resleeved cooper s master cylinder and rear wheel cylinders. it also had a standard bias valve. After being fitted a few years ago and some long storage periods these were a bit shagged and especially after the lengthy transport some corrosion siezed up the caliper pistons. I wanted to install the hydraulic handbrake when i was renewing the rest and also wanted the convenience of an adjustable bias plumbed in the line upstream of the handbrake. NOW it has cooper s discs and new 2 spot calipers, a new cooper s master cylinder and rear wheel cylinders. The only difference in terms of volumes is that there is now the bias valve and hydraulic handbrake and the original bias valve is replaced by a T-piece. So there is no difference in the ratio of master to caliper or wheel cylinders. No difference in the ratios means that there should be no difference in pedal feel and effort. In theory the hydraulic handbrake makes no difference to the amount of pressure felt at the rear wheel cylinders when using the footbrake. I think that Simon and Matt may have hit on the cause in the bias valve. Even with it fully adjusted to minimise the rear bias, the pedal still has to move too far. The bore of the Tilton one might be much less than the standard Mini one, which could cause the problem. thanks for the suggestions michael |
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| Author: | 1310/71 [ Tue Nov 18, 2008 7:55 am ] |
| Post subject: | |
Just as a thought, have you tried ringing or emailing Arthur or Stewart direct. They may have already "been there, done that" and can tell you straight away what to try. The cost of the O/S phone call may be offset by the lack of angst it is causing you. Ps, you could always try Skype 
KB |
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