Author Topic: Pedal height (Read 1922 times)

winabbey · « **Reply #30 on:** June 23, 2019, 07:04:05 PM »

Quote from: Terry on June 23, 2019, 05:56:33 PM

The bit of padding you mention was there when you pulled the pedal box out is usually just a piece of hessian matting, like old style carpet underlay, which the factory fitted there to quieten things down.

If you are talking about a small piece of hessian that sits on the bottom of the cavity where the two master cylinder push rods meet the pedals then I think it's original purpose was to absorb any leakage of fluid down the push rod.

Mokee Moke · « **Reply #31 on:** June 23, 2019, 07:28:22 PM »

Hi Terry,

Advice acknowledged and I agree with your assessment.

I will have a re-think, as I wasn't particularly comfortable with the solution either; but I am reasonably confident the pedals need to be level to pass roadworthy. I suspect the bit of rubber mat was bonded under the brake pedal lever and not under the clutch pedal lever to bring the pedals level for RWC in Qld (it was definitely fitted after the vehicle's total rebuild in 2004). In the short period I drove the vehicle before undertaking the maintenance actions, I didn't notice anything amiss with the brakes, which is why I felt the solution should be ok. But, I agree with your assessment and will remove the rubber mat.

Maybe one solution might be to make an adjustable length brake pushrod. This would enable the pushrod to be shortened to bring the brake pedal down to the same height as the clutch pedal without affecting the pushrod travel inside the m/c.

Thank you for taking the time to check your collection of Mokes for their pedal characteristics. Based on your observations, do you think the clutch pedal height is constant between all your Mokes? That is, at spec height?

I ask this because you have a single brake m/c and tin-type clutch m/c configuration. If I understand correctly, in this configuration the pedal heights are equal. If so, then my clutch pedal must be at the correct height too; meaning that my brake pedal height is not in spec (to high).

Cheers,
Greg

Terry · « **Reply #32 on:** June 23, 2019, 09:46:05 PM »

Hi,

I will take a couple of measurements in the morning when it is not quite so cold.

I don't really understand why the pedal could cause it to fail a roadworthy/inspection. ADR 31 doesn't mention pedal height in any of its assessment of the Brakes, https://www.legislation.gov.au/Details/F2010C00150. And while searching I found that there are modern vehicles that come with brake pedal adjustment devices built into them.

I did read something about what I vaguely recall knowing and that is that the brake pedal and accelerator pedal should be at different heights to reduce the likelihood of the go pedal being pushed when it should have been the brake.

Terry

cheezle · « **Reply #33 on:** July 13, 2019, 09:05:05 AM »

Hi all
I had the moke inspected for licensing today , with the peddles not at the same hight , the inspector did comment on it , he told me there wasn't any rule on hight differences ,

Cheers
Cheezle

Mokee Moke · « **Reply #34 on:** July 13, 2019, 08:59:35 PM »

Thanks for the update Cheezle. Its good to know the pedal height difference won't stop me getting a RWC in the future.

However, I still haven't got my clutch up and running yet, as my new clutch master cylinder won't hold pressure. Arrrrrrrgh!!! I have tried all the tricks mentioned under a different thread, but to no avail. So I tried installing the bleed screw into the master cylinder and bleeding the master cylinder, which worked fine, but when you applied steady pressure to the clutch pedal (bleed screw closed) the pedal slowly went to the floor.

I suspect incorrect cup fitted for the bore. Going to see if I can get another new clutch m/c of the guy I brought it from in Queanbean

Best regards,
Greg

Mokee Moke · « **Reply #35 on:** July 25, 2019, 06:23:15 PM »

Good news! Alan, from Classic Motoring, has provided me with a new replacement clutch master cylinder. Will fit this weekend and give an update.

cheezle · « **Reply #36 on:** July 26, 2019, 08:13:45 AM »

Hi Greg
can you please measure face to centre of pin hole of the two cylinders when you have both side by side

Cheers
Cheezle

Mokee Moke · « **Reply #37 on:** July 27, 2019, 08:01:59 PM »

Hi Cheezle,

Success! New clutch master cylinder working like a champ.

Distance from face of clutch m/c flange to centre of pin hole is 70mm. Brake m/c was already installed. I will remove tomorrow and measure.

Cheers, Greg

cheezle · « **Reply #38 on:** July 28, 2019, 11:29:34 AM »

Hi Greg
Could you give me the part number of the 70mm MC , I looked back on my post and the one I fitted was 68.2 mm ,doesn't sound like much , when you have pin out 1.8mm would most probably about all it needs without the shim under it ,
Has your new MC got tin or plastic reserver on it ?

cheers Cheezle

Mokee Moke · « **Reply #39 on:** July 28, 2019, 01:16:42 PM »

G'day Cheezle,

Part number of clutch m/c: GMC1008. Taken from invoice; no visible part number on item. Alan (Classic Motoring) says the cylinders come from Italy; manufacturer is LPR. This part is the plastic reservoir variant. Pushrod length is 70mm.
Old cylinder was tin can variant. Pushrod length is 70mm.
Measured brake m/c pushrod from flange face to pin hole centre: approx 74mm.
Compared brake m/c pushrod difference to clutch m/c pushrod by placing end to end. Clutch m/c pushrod is approx 4-5mm shorter than brake pushrod.

Photos to follow.

Pushrod comparison = 4mm (approx)

Tin can clutch m/c pushrod = 70mm (approx)

Tandem brake m/c pushrod = 74mm (approx)

Cheers,
Greg

Mokee Moke · « **Reply #40 on:** July 28, 2019, 01:30:11 PM »

Another update:

I removed the pushrod from the tin can m/c and compared it to the old tandem brake pushrod: same length

cheezle · « **Reply #41 on:** July 29, 2019, 08:07:34 AM »

Hi Greg
Thanks for the photos , so the problem is the brake MC ,its to long , I think that should be a easy fix

Cheers
Cheezle

Mokee Moke · « **Reply #42 on:** July 29, 2019, 06:21:30 PM »

I agree. I have emailed Alan to see if the manufacture has shorter pushrods. If not, then I'll have a chat to metal work shop to see if I can shorten the rod by 4mm. It should be relatively simple operation; suggest cut clevis off at base of shaft, then remove 4mm of rod, then weld clevis back on end of shaft.

As its the brake pedal, I don't think 4mm of travel at the end of the pushrod's stroke will have any impact on the brake effort. When applying the brake pedal it shouldn't move much from rest to full lock-up (perhaps 25-50mm max).

Terry, any thoughts on shortening the pushrod?

Cheers,
Greg

Terry · « **Reply #43 on:** July 30, 2019, 09:50:55 PM »

Hi,

if you shorten the rod by 4mm then the pedal will be proportionally closer to the floor, by how much I couldn't say, but it will be a multiple of 4mm.

Whether that amount means your pedal will hit the floor before it has been able to apply full pressure will depending on a lot of things like how well adjusted the brakes are, the wear in clevis pin holes, the handbrake adjustment etc.

Given that thousands of people have spent thousands of hours over the years fighting against the fairly average Moke(and Mini) braking system and trying to get the pedal to have full brakes before it hits the floor, it does seem to me to be counter intuitive to purposely move the pedal closer to the floor just so it looks right when at rest.

Terry

cheezle · « **Reply #44 on:** July 31, 2019, 07:21:27 AM »

Hi
Maybe they added the 4mm to solve the problems you are describing Terry

Cheers
Cheezle