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Re: Front Brake Cylinder Small Bolt Head Size

Posted: Tue Sep 30, 2014 2:42 pm
by svenedin
OK. Thanks. I'll try one more time to get the set screws out and if that fails I will take the backplate off. In any case the backplate is rusty Behind and could do with some tlc.

Re: Front Brake Cylinder Small Bolt Head Size

Posted: Fri Oct 03, 2014 8:13 am
by svenedin
Well I tried some different spanners and sockets and it is still a complete mystery what size the head is on these small set screws. I can only assume that they are worn and corroded and that has made it impossible to find the right spanner.

11/32 AF too big, 2 BA feels OK but slips with torque. 1/8 BSW far too big. Closest I can find is 8 mm (very close) or 5/16 AF but both are too small. I am going to file the screw head down to accept an 8 mm socket. I could take the backplate off but I'm not sure it would get me any further because I don't have a vice and it would be difficult to drill the screw heads out trying to hold the backplate and the drill.

Re: Front Brake Cylinder Small Bolt Head Size

Posted: Fri Oct 03, 2014 3:28 pm
by svenedin
Further update on this. Those horrible small set screws are out (on one side at least). Hurray! In the end I took the hub off and then the backplate. Looking at the backplate on the bench I could see there was no way the screws would ever come out normally. The heads were too rounded even on the one I hadn't mauled and mashed. With one screw I cut the head off with a dremel cutting wheel. The other came out by hammering a 5/16 AF socket onto it and a long torque wrench handle. The bigger set screws were not a problem. I think that the small set screws on my car were 11/32 AF but I appreciate they seem to vary. The new ones I have are definitely 11/32 AF.

Does anyone have any tips on refurbishing the brake drums, back plates and suspension parts? I am chemically de-rusting them after using a wire brush but I wonder how to protect them afterwards. I assume brake drums are not normally painted as they get very hot and need to dissipate heat but some protection would be good. As to the backplates, these were painted black. Would any tough black car paint do or do they need high-temperature engine type paint? Then what about the suspension parts (which are very rusty)?

Re: Front Brake Cylinder Small Bolt Head Size

Posted: Fri Oct 03, 2014 3:42 pm
by alexmcguffie
Good you're finally getting somewhere :)

Personally, I'd buy new drums, you'll notice the difference if your current ones are old and worn. As for painting, if you want it to last go for powder coating. It lasts for ever! Everything can be done apart from the track rod ends and dampers which contain oil/grease which solidifies when the powder is baked on. Trunnions can be done too but give everything a good de-grease and mask any areas that don't want painting(threads, stub axles etc) with insulating tape.

I've always painted drums/calipers with 3 coats(2 x smoothrite + 1 x Hammerite). Its worked well for over 15 years on one of my cars. Other more exotic brake paints are available though.

Re: Front Brake Cylinder Small Bolt Head Size

Posted: Fri Oct 03, 2014 4:56 pm
by svenedin
Alex, thank you for your reply. Yes, I think I will buy new drums. They are somewhat scored and clearly worn. At some stage, long ago, I suspect they have been gouged by pads worn down to the rivets.

I rather wanted to clean out the bearings whilst they are off the car. I am aware that any dirt contamination could do a lot of damage. The grease inside appeared to have "gone off" if it is possible for grease to do that. Certainly it looked horrible. Can I take the bearing apart with only basic tools? I would thoroughly clean, re-pack with grease and reassemble. I do have new oil seals but they are not quite the same as the old ones which are metal with a rubber inner. The new ones seems to be rubber coated metal of some sort.

So the parts are sent away to be powder coated? Are there lots of firms that will do this? I believe there is a chap in the USA who will refurbish lever acting dampers (and they could be powder coated then) but carriage would be outrageous. Is there anyone in the UK who can do them? The parts suppliers sell refurbished exchange dampers so who does it for them?

Re: Front Brake Cylinder Small Bolt Head Size

Posted: Fri Oct 03, 2014 5:18 pm
by alexmcguffie
Where in the world are you? Your user name suggests Scandinavian...?

There are plenty of places in the UK that do powder coating. I've always managed to find a local company so I can deliver the parts myself.

I don't think I'd send dampers to the US! Drain them and re-fill with heavier oil and paint by hand should do the job.

Grease can dry up or harden, especially in trunions so definitely give them a good clean and re-grease when you take them off. Wheel bearing can be removed with basic tools (drift etc to tap them out of the hub) but ideally a big vice or press would help to re-fit them. You could use a socket of the right diameter to tap them back in.

Re: Front Brake Cylinder Small Bolt Head Size

Posted: Fri Oct 03, 2014 5:40 pm
by svenedin
I'm in Surrey. Haha, no I wouldn't send dampers to the USA but I go there quite a lot so I could actually take them over. Customs might baulk at my luggage contents though. I'll look up powder coaters in my area. Black powder coating or some other colour? I'll investigate taking the bearings out.

Re: Front Brake Cylinder Small Bolt Head Size

Posted: Fri Oct 03, 2014 7:24 pm
by alexmcguffie
I'm sure you'll find somewhere in your area. As for colour you can have any colour under the sun but black is a safe bet! If someone else is having the same colour done at the same time it can often reduce your price as they don't have to chance colours in their guns.

Re: Front Brake Cylinder Small Bolt Head Size

Posted: Fri Oct 03, 2014 7:54 pm
by bmcecosse
The 'garden gate' black paint from Poundland is excellent - thick and sticks like sh!t ... pretty much like a traditional 'chassis black' paint'. Powder coating is much over rated and way OTT for a Minor ! It chips easily.... and certainly not inexpensive! Just wire brush the parts - chemically derust if you can - then a good coat of the black paint and they will be fine for many a year. Are the drums 7" or 8" ?? If scored - yes you probably will be better with new drums, but I wouldn't justify that expense on the early 7" drums. (I would instead upgrade to 8" (or 9" !!)). Try to get decent 'Mintex' branded brake shoes....some of the other suppliers seem to be less 'efficient' shall I say at stopping the car...

Re: Front Brake Cylinder Small Bolt Head Size

Posted: Fri Oct 03, 2014 9:44 pm
by svenedin
I have had good results with "garden gate paint" from Toolstation. I have really used it on my garden gate with good results. The brand is "Flag", xylene based.

How do I take this bearing apart and is it worth it just to clean it out? I can't find basic instructions in my books. The front ball race appears to sit against a lip so it can come put forward. The rear race seems to held in by the oil seal. The grease packing is very old and filthy and quite probably contaminated with dirt. The bearings run well without grind or play so I don't think they need replacing.

Re: Front Brake Cylinder Small Bolt Head Size

Posted: Fri Oct 03, 2014 10:06 pm
by MarkyB
I'm pretty sure the original finish is just a single thin coat of cellulose.
No preperation, no under coat.
It survives remarkable well so anything better will last even longer.

Re: Front Brake Cylinder Small Bolt Head Size

Posted: Fri Oct 03, 2014 10:20 pm
by bmcecosse
Yes that's it - front bearing forward and rear bearing will come out after the oil seal is removed. Take great care to note which round they are fitted - and put them back exactly as they come out. Frankly - I would clean them without removal - then repack with new grease