likaleica Posted February 17, 2015 Report Posted February 17, 2015 (edited) I'm hoping someone can de-mystify a strange problem I've encountered trying to re-fit my reconditioned brake master cylinder. This is a RIGHT HAND DRIVE CAR. Whichever way I fit the unit, either the clutch pedal fouls it or the brake pedal does. When I position the master cylinder's mounting flange to the transmission side of the mounting plate on the frame (nearest the centre of the car) , the clutch pedal lever fouls the reservoir part of the master cylinder. When I reposition it so the mounting flange is on the door side of the frame mounting plate (nearest the outside of the car), then the brake pedal lever fouls it. I haven't disturbed the positions of the brake pedal or clutch pedal. Which side of the mounting flange SHOULD the master cylinder be mounted - and why is mine fouling in whichever position ? All guidance gratefully received! PS I have not been able to fathom how to post a photo of the master cylinder on here so I have posted one in the Gallery Technical Mechanical area Edited February 17, 2015 by likaleica Quote
P15-D24 Posted February 17, 2015 Report Posted February 17, 2015 You can go to Help -> Site Help Topics for step by step instruction on posting images. The Help menu is in the dark brown header bar just under the site logo. Also if you have posted your pics in the gallery you can access them in a thread by clicking on the "My Media" button next to the smiley face in the toolbar. Sorry can't help you with your original question Quote
desoto1939 Posted February 17, 2015 Report Posted February 17, 2015 If I remeber correctly the 39 MC is the same as my 39 Desoto. There should be a moutning flange that the MC attaches to on the two bolt holes at the bottom of the MC unit. IS the flange still on the frame of the car or was that removed when you sent the MC out to be resleeved and they might not have sent that back to you. Also check your parts book it shoudl show a picture of the flange. Rich HArtung desoto1939@aol.com Quote
1952B3b23 Posted February 18, 2015 Report Posted February 18, 2015 (edited) These are pics of my 39 Plymouth coupe MC mounting. If you are sitting in the drivers seat looking at the MC it mounts on the right side of the bracket that attaches it to the frame. Hope that helps. EDIT: My car is a US car (left hand drive), i didn't see the part in the original post about the car being a right hand drive. I hope these pics still help you in someway.-Chris Edited February 18, 2015 by 1952B3b23 1 Quote
Dave72dt Posted February 18, 2015 Report Posted February 18, 2015 RIGHT HAND DRIVE , guys. Placement may be a mirror image of the left hand drive and then again, may be unique to right hand. I wouldn't expect a lot of diversity in placement within a year or two of production. This may be a question best answered by some of our Oz members. Quote
Andydodge Posted February 18, 2015 Report Posted February 18, 2015 From memory its exactly the same setup as the yanks used, ie a mirror reverse to the extent that the "factory" approved OZ workshop manual uses LHD pics.......have you left the stamped metal bracket that goes between the M/c and the chassis in place?.........the M/c doesn't bolt direct to the chassis but to this bracket that does.....is the m/c you are trying to fit the EXACT same one that was on the car?......or is it a rebuilt exchange or NOS one either of which maybe from the USA and have a different mounting to the RHD cars.........I have not had the stock braking system since 1975/76 and I sold the rhd 1941 Plymouth a couple of yrs ago and never took pics of the brake/clutch area so I dunno how else to help..........it seems strange that you are having problems..............andyd Quote
likaleica Posted February 18, 2015 Author Report Posted February 18, 2015 Thanks for the replies and pix guys......it is the original MC and I did not remove the mounting flange that bolts to the frame, only the bolts holding the MC to that. In Chris's pix of the LHD set-up the MC is mounted nearest the brake pedal lever.......and if mine mirrors that it would be mounted on the right hand side of the mounting flange - the position in which it fouls the brake pedal! I'm now wondering if I need to back off the brake pedal stop bolt and increase the length of the MC piston rod - so that the brake pedal in the off position is nearer the driver and further from the MC unit. That way the brake pedal may not foul ??? Going to give it a try anyway.....and let you know Quote
1952B3b23 Posted February 18, 2015 Report Posted February 18, 2015 Thanks for the replies and pix guys......it is the original MC and I did not remove the mounting flange that bolts to the frame, only the bolts holding the MC to that. In Chris's pix of the LHD set-up the MC is mounted nearest the brake pedal lever.......and if mine mirrors that it would be mounted on the right hand side of the mounting flange - the position in which it fouls the brake pedal! I'm now wondering if I need to back off the brake pedal stop bolt and increase the length of the MC piston rod - so that the brake pedal in the off position is nearer the driver and further from the MC unit. That way the brake pedal may not foul ??? Going to give it a try anyway.....and let you know I'd say to post up some pics of the setup and the problem areas. I mean re-installing the MC on my car was pretty easy. It shouldn't be causing you so much grief. You speak of increasing the length of the MC piston rod so that the pedal is closer to the driver... if i remember correctly you should have about 1/4 inch of pedal free travel before the piston rod engages the MC. There is a photo of this "free travel" in the brake section of the car service manual. Maybe someone has a photo of that page(s). Good Luck, -Chris 1 Quote
likaleica Posted February 19, 2015 Author Report Posted February 19, 2015 Well, it is sorted. I took the MC off and repositioned it so the unit's flange was on the left hand side of the mounting flange on the frame (so the unit is nearest the clutch bellhousing) - and both pedals now clear. I can't work out why the clutch pedal fouled the first time I did this.......anyway thanks once again for all the help, guys! Now I'm going to bleed the system and hopefully I'll have brakes for the first time since I bought the car! 1 Quote
Andydodge Posted February 19, 2015 Report Posted February 19, 2015 Pleased you have sorted it out............hope its all good now........andyd Quote
Roadkingcoupe Posted February 19, 2015 Report Posted February 19, 2015 after bleeding the brake system the next challenge will be the alignment of the brake shoes to achieve full contact. Bleeding the brake system will activate the wheel cylinders and the shoes will/should press against the drum. There are two adjustments a major/minor (micro/macro) at the top and bottom of the back of the brake shield. The goal is to get the maximum amount of brake shoe to press against the brake drum. This has been discussed many times on the forum and includes the use of a specialized tool including the Ammco 1750? Others have manufactured homemade versions. If you have an used (no longer needed) extra brake drum you can cut out a "window" at the shoulder and use that as a way to adjust the brake shoe alignment. There is a wealth of information on the forum....just do a search. When properly adjusted the brake should be quite effective at stopping the car. If they are poorly adjusted the braking distance will be less then ideal. 1 Quote
likaleica Posted February 23, 2015 Author Report Posted February 23, 2015 Though I have bled the system and the pedal is now firm with no sponginess, only one of the drums is being braked properly (the one nearest the MC.) The other three show no braking effort at all (the car is jacked off the ground all round and I can turn them with ease when an assistant operates the brake pedal). I carried out the "minor" adjustment on the drums detailed in the Plymouth manual and from experience with other old cars they appeared to be OK. I've read what Roadkingcoupe said about brake shoe alignment - but I am wondering if the problem in this case is seized wheel cylinders from lack of use. The car had been in storage for some years after a very thorough and good restoration when I bought it 10 months ago. Unfortunately the owner had died so details of what was done on the brakes was lost too. All the brake lines had been renewed and by the look of the bleed nipples, the wheel cylinders were either new or reconditioned. There was no braking effort at all, but the master cylinder was leaking buckets - so I had it reconditioned and hoped that was the cause. I'd be grateful for thoughts on this...and also to hear from anyone who's made their own tool for centering the brake shoes as I'll have to do this anyway whether or not I strip out all the wheel cylinders....... Quote
Roadkingcoupe Posted February 24, 2015 Report Posted February 24, 2015 Interesting that the only wheel cylinder working is closest to the MC Have you tried bleeding the wheel cylinders starting at the furthest from the MC and then one at a time move closer to the MC. Of course if the wheel cylinders are "frozen" the they need to be disassembled, honed out, rebuilt or replaced. Though I have bled the system and the pedal is now firm with no sponginess, only one of the drums is being braked properly (the one nearest the MC.) 1 Quote
Roadkingcoupe Posted February 24, 2015 Report Posted February 24, 2015 If you have an used (no longer needed) extra brake drum you can cut out a "window" at the shoulder and use that as a way to adjust the brake shoe alignment. I'd be grateful for thoughts on this...and also to hear from anyone who's made their own tool for centering the brake shoes as I'll have to do this anyway whether or not I strip out all the wheel cylinders....... 1 Quote
Andydodge Posted February 24, 2015 Report Posted February 24, 2015 Did you pull any of the wheel cylinders apart? or just the master cylinder?.............if just the m/c I'd be biting the bullet and checking all the wheel cylinders...........you should be able to disassemble them without stuffing up the cylinder seals and dust caps........the bores maybe shot or the pistons seized......... only one way to find out.......good luck............andyd 1 Quote
likaleica Posted February 24, 2015 Author Report Posted February 24, 2015 Thanks again fellas - looks like the consensus is to "bite the bullet" as andyd aptly puts it and strip those wheel cylinders down. Oh well, so be it! Being in the UK, goodness knows where I will get a spare brake drum........but if anyone has a picture of where the window is cut in it, that would be extremely useful! So it's overalls on again - and I'll keep you all posted on how I get on ! Quote
_shel_ny Posted February 24, 2015 Report Posted February 24, 2015 (edited) I don't think that you can bleed the brake cylinder on an individual wheel if the cylinder is frozen.EDIT: well, not properly bleed it. Adjustments are made to close tolerances (later .006", 39 may vary heel to toe) with the drum involved for the adjustment of that drum at that specific position. Cutting a window in a brake drum will allow the adjustment to be made only with the drum that you cut, not another drum.(unless it is exactly the same size) It will allow you to get close, but it will not provide that final proper adjustment that you need for uniform contact on the drum. It sounds like you have already done some close adjustments as you say you have a firm pedal. The best way to bleed the brakes, and check cylinder operation is to pull the drums, and clamp each set of shoes. Edited February 24, 2015 by shel_ny 1 Quote
_shel_ny Posted February 24, 2015 Report Posted February 24, 2015 The best home made tool that I have seen for centering the brake shoes is the one constructed by forum member David Strieb. I did not actually end up using the one that I got from David before I sold my car, but it is by far the most impressive that I have viewed. The PVC, and or wooden ones that have been discussed/shown here, and on some other forums do not seem, at least to me, that they would have the stability (sturdiness) needed to stay accurate. Accurate being a relative term, as we are just shooting for close centering. PM me if you would like mine. 1 Quote
1952B3b23 Posted February 24, 2015 Report Posted February 24, 2015 That's a great idea with that homemade tool. Thanks for posting those pics. Quote
Andydodge Posted February 24, 2015 Report Posted February 24, 2015 Lika..........being in the UK I suppose you would also have a distinct lack of spare brake drums to cut up..........lol......that tool that Shel made looks like a worthwhile execise, maybe he could loan it to you, just post the main threaded piece or its dimensions.........aren't old cars fun...............lol.............andyd Quote
_shel_ny Posted February 25, 2015 Report Posted February 25, 2015 Lika..........being in the UK I suppose you would also have a distinct lack of spare brake drums to cut up..........lol......that tool that Shel made looks like a worthwhile execise, maybe he could loan it to you, just post the main threaded piece or its dimensions.........aren't old cars fun...............lol.............andyd That tool was made by forum member David Strieb. I did not have the tools, or skills to make one. The critical item in the construction would be the very common 3/4" nut. Other parts would be common items of the builders choosing dimension wise. Most critical is the precision positioning of the rod coming off the nut so that the rod to the shoes is at 90 degrees. Quote
Andydodge Posted February 25, 2015 Report Posted February 25, 2015 Shel....so the large 3/4" nut is just a neat fit over the axle, it does not screw onto the axle thread?.............andyd...... Quote
likaleica Posted February 25, 2015 Author Report Posted February 25, 2015 This is all terrific guidance guys - thanks very much indeed! I'm going to pull the drums and clamp the shoes first off, and try bleeding again. And also chase up the home made tool! Only problem here is the showery cold weather - I'm working in the open so it slows the job immensely...... Quote
desoto1939 Posted February 25, 2015 Report Posted February 25, 2015 I was looking in My Plymounth 1929-39 MAster PArts books Vol 1 and 2 and I saw that there was note regarding RHD cars and the MC. There was a note that there isa specific heat shield that was used on the RHD cars. I would think this was used becasue of the exhaust manofold and exhaut pipes being near the MC and not not heat up the brake fluid. Not sure if you have the heat shield but just thought I would mention it. I am sorry but there is no picture of the heat shield so I can not send you any picture of what it should look like and how it attaches. Rich HArtung desoto1939@aol.com Quote
_shel_ny Posted February 25, 2015 Report Posted February 25, 2015 Shel....so the large 3/4" nut is just a neat fit over the axle, it does not screw onto the axle thread?.............andyd...... 3/4 -16 nut threads onto axle. Cheap nut, as it does not need to be the special castle nut. Quote
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