How to adjust TC Brake M/C rod to peddle angle

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pleask
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How to adjust TC Brake M/C rod to peddle angle

Post by pleask » Thu Feb 18, 2016 8:08 am

In the TC's Forever book it shows the right and wrong way for the brake M/C push rod to be in relationship to where it threads in to the brake peddle arm I'll call it. Mine, of course, is in the wrong position.

I have tried to adjust the M/C up and down to no avail, when I thread the "ball joint" threaded rod all the way forward that of course changes drastically the brake peddle position which I do not think is a good idea.

The operation is smooth, nothing hits but still I don't think it's right to leave it as is,
How do I correct this please, or do I?

Pat
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Duncan M
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Re: How to adjust TC Brake M/C rod to peddle angle

Post by Duncan M » Thu Feb 18, 2016 4:47 pm

Pat-
Doesn't look bad. You tried the TC's Forever oval hole adjustment? Loosen the big nut and move the whole "box" that surrounds the m/c? I know the book has a diagram of a perfect setup, but I don't know that anybody actually achieves it. Or maybe I need more work on mine, too?

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Duncan M
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Re: How to adjust TC Brake M/C rod to peddle angle

Post by Duncan M » Thu Feb 18, 2016 4:47 pm

Pat-
Doesn't look bad. You tried the TC's Forever oval hole adjustment? Loosen the big nut and move the whole "box" that surrounds the m/c? I know the book has a diagram of a perfect setup, but I don't know that anybody actually achieves it. Or maybe I need more work on mine, too?

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pleask
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Re: How to adjust TC Brake M/C rod to peddle angle

Post by pleask » Thu Feb 18, 2016 5:54 pm

Hi Duncan, yes I tried moving the M/C up and down (I thought I said that in my blurb). I guess I'll have to go with it "as is" then unless anyone else has a thought?
Thanks, Pat

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Steve Simmons
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Re: How to adjust TC Brake M/C rod to peddle angle

Post by Steve Simmons » Thu Feb 18, 2016 8:16 pm

Mine is practically perfect but it was never that bad to start with. Maybe the push rod is the incorrect length?
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pleask
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Re: How to adjust TC Brake M/C rod to peddle angle

Post by pleask » Thu Feb 18, 2016 8:34 pm

Hi Steve, good point on the push rod. I did have two push rods, and when I put the longer one in (1/2" longer) it was much better. As bad as this may sound.. could you kindly take a measurement of your push rod? And let me know of course the start/ending point?

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Steve Simmons
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Re: How to adjust TC Brake M/C rod to peddle angle

Post by Steve Simmons » Thu Feb 18, 2016 11:42 pm

I'm not sure how to measure it in place since the end is inside the MC. But it was supplied by Moss Motors about 5 or 6 years ago. The overall length was slightly too long to fit with the MC in place so I put a couple of threads off the end and it just barely made it. Can't find a photo but I'll try to remember to get one.
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ian theobald
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Re: How to adjust TC Brake M/C rod to peddle angle

Post by ian theobald » Sun Feb 21, 2016 5:56 pm

Interesting as I had the same problem but only when bleeding brakes .
My brake rod though not as bad would scrape on the M/C on it,s maximum stoke until bled but noted that rod inside M/C has a rounded end from memory allowing for it to be pushed on an angle.

It is possible that different cylinders have slightlty different length rods inside. My old one was very rusty and pitted and never bothered to check or compare. ]
The master cylinder can be fun to remove with it,s large nut that is recessed and ended up going to local tool place and purchasing some large ring spanner that will only ever get used once but at least was cheap .
[Not King Chrome or Sidchrome that are made here in Oz] .

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Steve Simmons
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Re: How to adjust TC Brake M/C rod to peddle angle

Post by Steve Simmons » Sun Feb 21, 2016 6:47 pm

It also just occurred to me that if you thread the rod further into the pedal, it will improve the angle. But then the lower half of the rod will be to short. So I wonder if you need a longer lower section, or if the master cylinder is too far away
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pleask
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Re: How to adjust TC Brake M/C rod to peddle angle

Post by pleask » Sun Feb 21, 2016 7:24 pm

Hi Steve, all. Yes if I thread the push rod further in to the pedal arm the angle lessens. How ever, as I said in my post when I do that the pedal arm moves backwards from the clutch pedal, and no longer comes to rest on the fixed point of the chassis, is this acceptable?
Thanks, pat

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Gene Gillam
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Re: How to adjust TC Brake M/C rod to peddle angle

Post by Gene Gillam » Mon Feb 22, 2016 3:22 pm

Pat,

On both of my cars the angle is about the same as yours...I wouldn't worry about it.

Gene

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Re: How to adjust TC Brake M/C rod to peddle angle

Post by Eric Worpe » Tue Feb 23, 2016 12:58 pm

Hi Pat, The push-rod should be adjusted until there's about 1/2" free play at the pedal before the piston starts to be operated. At this point the "ball" on the articulated joint should be slightly forward of a vertical line that passes through the centre of the pedal's bearing shaft. The "ball" will then pass through the vertical line and possibly beyond as the brake pedal is further depressed to engage the brakes.
When the "ball" is directly below the pedal shaft, the push rod ought be horizontal. The adjustment on the master cylinder bracket should allow for this set up. If the push rod is too short, the push-rod adjustment screw will have been wound down so far, that the "ball" is too far below the horizontal line projected through the centre of the master cylinder. This could then account for the angle of your push rod.
The drawing in Mike Scherrell's book is a bit misleading, as the crucial point is that the "ball" should be directly below the pedal shaft when the brake shoes are engaged, giving a horizontal thrust through the push-rod to the piston. It seems that you may need to check the length of your push-rod, as some replacements may not be right.

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pleask
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Re: How to adjust TC Brake M/C rod to peddle angle

Post by pleask » Tue Feb 23, 2016 5:53 pm

Thanks Eric, I do have two push rods and one is about a 1/2" longer than the other (does not mean either of them are correct). But the problem is I don't know how long the correct push rod is having never owned (or built) a TC before. Pat

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Re: How to adjust TC Brake M/C rod to peddle angle

Post by Eric Worpe » Wed Feb 24, 2016 4:47 am

Hi Pat, I noted that you found the longer push-rod was a better fit; from your photo it seemed that the adjustment screw was wound down excessively, resulting in the push-rod being angled to the horizontal. Why not consider using the push-rod that gives the best horizontal alignment?
Regards, Eric.

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pleask
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Re: How to adjust TC Brake M/C rod to peddle angle

Post by pleask » Wed Feb 24, 2016 9:02 am

Morning Eric, as things have turned out as I have a leak in the banjo fitting (other post) I have to take everything apart (arg, again) so I'll reassess this whole angle thing. When I had a shorter push rod installed the angle was worst and something was scraping inside the MC. When the longer one was used no more noise... if I adjust either push rod to peddle arm the part of the peddle you place your foot on moves further forwards than that of the clutch peddle and should the two not be more or less equal to each other?
Pat

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Re: How to adjust TC Brake M/C rod to peddle angle

Post by Eric Worpe » Wed Feb 24, 2016 9:53 am

Afternoon Pat, There should be a return spring on the brake pedal ( in addition to the brake switch spring ), which ought to return the pedal so that it comes to rest on a stud, defining the position of the pedal at rest. The push-rod adjustment is then altered so that about 1/2" of play of the foot pedal takes place before the piston starts to move. If the push-rod length is correct, the ball joint should be almost below the pedal shaft at this setting.
Regards, Eric.

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Re: How to adjust TC Brake M/C rod to peddle angle

Post by Steve Simmons » Wed Feb 24, 2016 10:06 am

Just to be clear, the measurement of 1/2" is at the top of the brake pedal itself, where your foot goes, not down at the piston. The play is to allow for heat expansion. Without a slight gap, you could end up with dragging brakes when things heat up!
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Re: How to adjust TC Brake M/C rod to peddle angle

Post by Steve Simmons » Thu Feb 25, 2016 10:32 am

Here is a photo of my push rod. It's basically level, perhaps slightly angled down.
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pleask
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Re: How to adjust TC Brake M/C rod to peddle angle

Post by pleask » Thu Feb 25, 2016 6:06 pm

Thanks for the pic Steve and help Eric. I messed around with it today and reinstalled it (hoping I fixed the leak at the banjo at the same time) and now it looks more like your picture Steve... phew one problem over with. Now if that blankity-blank-blank leak is fixed I'll be a happy camper.
Pat

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Re: How to adjust TC Brake M/C rod to peddle angle

Post by Eric Worpe » Fri Feb 26, 2016 5:34 am

Thanks also Steve for your photo which comfirms that Pat's push rod was too short, thus forcing the push-rod's adjustment thread to be screwed out so that the ball joint was far below its correct position, resulting in the inclined push-rod.
Pat, you've picked up on and solved a particularly tricky problem caused by some incorrect push-rods that have come onto the market. Others may well find the same problem if they checked their master cylinder.

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