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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - TF disc brake conversion

The TF 1500 that I recently acquired has a Volvo 1800 engine conversion so it's not stock and probably never will be. The car was involved in a serious accident in it's previous life which damaged the left hand suspension and steering tie rods. I'm converting the front to MGA/B disc brakes and have several questions for those who have done the conversion.

Will the MGA wire wheel hub fit on the TF stub axle or do you have to use the MGA stub axle as a complete unit?

Do you need to shorten and rethread the tie rods?

Are there any modifications that need doing to the brake master cylinder.

I'm also installing a 3.9 MGB rear end so brake imbalance should be OK, I assume.

Thanks

Andy
Andy Preston

Andy.. The hubs are interchangeable.. A couple of years ago I took on a job on a 1954 TF. It had been fudged up by many people. I was starting on the front brakes when I noticed that they were 10" diameter in lieu of 9" as the TF should have been.
Many years ago I installed disc brakes on a TD but with memory loss being the second sign of old age I do not remember if I had to modify the tie rods. I do not think that if you retain the the TF stubs that it would be necessary to modify the tie rod lengths.
I do know that if you utilize the MGA/MGB set-up that you will have to shorten the tie rods. The upper link on MGA/MGB is approx 1" narrower and I had to create two spacers for each side.
Sandy
SANDY SANDERS

You have to use the MGA 1600 steering knuckles and levers or the TD/TF and early MGA (1500) levers will interfere with the disk. The swivel pins and the top snd bottom links are the same as the TD/TF and All MGA
See page 32 of the Moss Catalog for the different numbers.
The levers and steering knuckles are NLA, used is the only source.

You have to shorten the tie rods to make up for the different bend in the levers
Don Harmer TF8986

Thanks guys for your help. I'm using MGA 1600 complete stub axles and have also fitted MGA tie rods to the TF steering rack. They screw straight in to the end of the rack and are 3/8" shorter and the thread is 3/8" longer than the TF tie rods, so I'm assuming that with MGA track rod ends I should be OK.

Thanks again

Andy

Andy Preston

I bought by '53 TD about three months ago and I am dealing with similar questions. It has MGA front disk brakes and MGB rear drum brakes. Knock-off wires all around. The previous owner (since '57) is deceased, but from his notes I know that the tie rods were shortened. I want to replace the tie-rod ends, but don't know whether they are MGA or TD. From what Don says, they are likely MGA. Moss lists different tie-rod ends for the MGA than for the TD. I also want to replace the lower A arm bushings, but again Moss lists different part numbers for the MGA and TD, although apparently the MGB V-8 bushings will fit both. I think my lower A arms are TD. It has Spax shocks which are at least 25 years old, but still adjust. Andy, my TD has the MGA dual master cylinder and pedals; they work well, but I would rather have a cable linkage for the clutch and a master cylinder just for brakes. Anyway, the MGA front disks and MGB rear drums work just fine off of the MGA master cylinder. The B18 engine was probably installed over thirty years ago and runs quite well. The 3.91 gives a full range of usage out of the Volvo four speed, although I may install a five speed. At my age (same as the PO) this will be my last project car of many over the years. I like to drive what I'm working on, so I think I will stop typing and go for an evening drive. I haven't had an MG before, so any advice on my front steering/suspension parts would be appreciated.

Regards,

Bobby Loughridge
B. F. Loughridge

For what its worth, I didn't shorten our TD tie rods, but cut & welded TD and B steering levers together, lengthening them and positioning the tie rod ends nearly in front of the rotor.

I realize the steering will be easier but slower with slightly enlarged turning radius. My main concern has been matching the tie rod angles with the upper & lower arms to avoid bump steering issues.

I slapped that 3.9 B rear end in, too!

Master cylinder seems to have plenty of capacity for the disc calipers and B rear brake cylinders. I'd sure sleep easier if there was a dual circuit master in our TDs? ANYONE KNOW OF SUCH A CRITTER?
Jim Northrup

As far as the lower A arms go, I just put two new ones on the right front of the TF and I think the only difference between the T arms and the B arms is the B arms have the facility to attach a sway bar link, which is probably a good switch if you have any intension's of adding a sway bar in the future. PJ
P S Jennings

I had to shorten my Tie rod ends about a 1/4 inch. I am still using the original MC on my 51 and it holds the brakes just fine. We have another car in the club that has done the conversion and he too is using the original MC on the car.


Tom Maine (TD8105)

You must remove the small valve cup seal at the end of the plunger assembly at the outlet end of the master cylinder. This seal serves as a means to retain pressure in the braking system used on drum brakes. If left in place, pressure will be retained and your pads will drag causing extreme overheating and pad wear.

Call me if you would like talk about this situation.

Frank Grimaldi 843-838-0822
Frank Grimaldi

Thanks a bunch for that heads up Frank!
Jim Northrup

Bobby you've probably got the TD/TF tie rods if they ave been shortened and then will need to buy the TD/TF track rods ends. You can check which ones you have by measuring the diameter of them. The MGA ones are thicker and measure 0.620" and the TD/TF one measure 0.560" diameter. See attached photo MGA tie rod is one the left.

The lower A arms are universal to TD/TF, MGA and MGB except for the front arm on the later MGAs and MGB has a larger hole for a sway bar, but can also be used if you intend to fit a sway bar in the future.

The inner rubber bushing are universal and all the different types should fit. I'll probably be using the V8 bushing because I have alredy used them on my other MGs and like them, although I tend not to drive them in the rain so am not bothered about the corrosion problem.

I'm using the original brake master cylinder and Frank thanks for your advice about the small valve cup seal.

I'm using a separate Girling m/c for the clutch.

Thanks to all,

Andy


Andy Preston

Andy, thanks very much for the concrete info on the tie rods! I have the TD tie rods, as they measured .573 before I abrased the corrosion off. I will buy the TD/TF tie-rod ends and assume that the tapered hole on the end of the lever is the same. Regarding the non-return valve removal that Frank recommends, I should mention that my TD has been running the MGA 1600 front disk brakes for a number of years activated by an MGA 1500 master cylinder, which uses the non-return valve. The MGA 1500 uses all drum brakes while the MGA 1600 has disks on the front and drums on the rear. I'm ordering new disk rotors and calipers and was concerned that Moss Motors shows a different master cylinder part number for the 1500 and 1600, although they use the same rebuild kit. I posted a question on the MGA site about any differences between the two master cylinders and was advised that the only difference was that the 1600 mc had a taller lid. Both apparently have a non-return valve. That said, the main reason that I'm ordering new rotors and calipers is that I have a dragging pad on the right front wheel that is super-heating the rotor. On another note, our cars have a lot in common (I haven't measured my frame yet, but it is suspect) so I expect that I may be in touch with you on other matters. Although I live in Texas now, I spent my working years in Southern California where I had quite a few British cars. I knew every junk yard in San Fernando Valley!

Regards,

Bobby Loughridge
B. F. Loughridge

Bobby, before you order MGA parts from Moss you might want to check with Scarbaorough Faire first they are located in Rhode Island, and only sell MGA parts. I recently completed a 4 year restoration of a 1960 MGA Coupe and purchased most of my parts at SF. The owner is Cecelia and apart from talking your head off knows more about MGAs than anyone else. Give her a call, (1-888-MGPARTS) I think you'll find the prices and quality very attractive as well. They are cheaper and better than Moss, but delivery normally takes a week.

I also note that the non return valve is shown on the MGA m/c (so I must have one on my MGA) and don't have any problem with the brakes in fact they are fantastic.

Andy
Andy Preston

I dont understand what removing a seal will do to the MC. Mine car has had the A brakes for two years and the other one in the club for over 4 and we have never experienced any overheating. Drove the car today and did a hard test of the brakes over a long run and they are cool as a cucumber. Would think that if a MC kept pressure on the regular drum brakes that would not work either. I think the seal is to allow the recirculation of the brake fluid back to the MC.
Tom Maine (TD8105)

I can say, with certainty, that you must remove the small valve cup seal in the TD master cylinder if you are converting from drum brakes to disc brakes. If you don't remove this seal the braking system will retain pressure and the brakes will drag and cause sever overheating. I know this from personal experience with my TD conversion. The reason that the retained pressure does not cause a problem with drum brakes is that the springs that hold the shoes in place will overcome the retained pressure in the system and allow a small amount of clearance between the shoes and the drums.

I may be mistaken but I think that the calipers for the MGA and early MGB are the same. If this is true than you can purchase rebuilt calipers from most auto parts dealers,(Car Quest, Advance Auto, etc). You can also buy the calipers and many other common parts from Rock auto Parts:

http://www.rockauto.com/catalog/raframecatalog.php

There prices are very good even after adding shipping.

Check out their web site, you will be pleasantly surprised at their low prices especially for MGB parts.

Frank Grimaldi
Frank Grimaldi

The TD's mc has a small relief valve that releases pressure... actually it is a tiny, tiny hole from the cylinder up into the reservoir....Mine was clogged and the brakes stayed on....eventually locking on (that was a fun trip back to the garage)...
I was able to open it with a pin/needle .... i have seen welding tip files that should be small enough.... If you look down into the mc from the filler hole, there are two 1/4" (?) holes...one seems to be blank at the bottom, but there is the tiny hole in there.

Not sure if that is what this discussion is about or not....just sayin
gblawson(gordon- TD27667)

Thanks Gordon, that is what I thought about the TD MC.
Tom Maine (TD8105)

Frank, unfortuneatley the MGA calipers are completely different from the MGB ones. I know because I own an 1960 MGA Coupe and 2 MGBs. You can fit MGB calipers to the MGA steering knuckle but it requires an adapter plate for each side, which costs $300 from Moss.

If I can't find good MGA calipers I will have to go that way.

Thanks

Andy
Andy Preston

This thread was discussed between 17/09/2010 and 23/09/2010

MG TD TF 1500 index

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