Amazon: Rebuilding rear brakes 1966 Amazon

[fishyboy]

Hi all,
As part of my ongoing work to try and find out why the rear brakes lock up before the front disks on heavy braking on my '66 131 (https://www.volvoforums.org.uk/showthread.php?t=307757) I have decided to start with a overhaul of the rear drums. Hopefully, my mistakes may be useful to others.

My key sources of guidance are:-

1) a thread on this forum, but missing the photos (https://www.volvoforums.org.uk/showt...=109036&page=2)

2) the "green book" - http://www.volvoamazonpictures.se/do...manuals_en.htm

3) Nordicar video - https://www.youtube.com/watch?v=E-wghTDCPCM

4) Amazon Cars video - https://www.youtube.com/watch?v=7wEtIV_rvM0

5) IPD video - https://www.youtube.com/watch?v=4nlK3IRCRCc&t=19s

What could possibly go wrong?

Firstly, I set about removing the drums. I used a hydraulic puller (Photo) which removed the drums successfully on my 1968 1800S, but due to my error resulted in slight mushrooming of the half shaft (https://www.volvoforums.org.uk/showthread.php?t=304683). This time I made sure I threaded the castellated wheel nut on in reverse to prevent any slight mushrooming.

My first mistake was that I didn't screw in the central threaded shaft (which includes the hydraulic ram) far enough into the body of the puller (I had separated the two to go back into the box after using last time!) and on tightening the central shaft jumped out and stripped some threads (Photo 2). after a hour removing the damaged thread with a angle grinder I finally managed to remove the OS hub with quite a bang! (Photo 3).

On inspection there are no leaks on the wheel cylinders (which look original) and the pistons move freely so I'll reuse both. Ive cleaned up the brake lever, brake adjuster, brake shoe link bar and castellated nut (Photo 4). I'll replace the shows as the lining look like they are just starting to separate from the show (photo 5).

One question I have is that in the thread I inked to on this forum it mentions putting some anti slip on the half shaft Morse taper, while Rob at Amazon Cars says the shaft must be completely dry when refitting the hub. Any views?

Secondly, I plan to clean up the outside of the drums and paint with HT Brake Caliper paint. what should I do to the inside of the back plate. At the moment it has a little surface rust and was wondering whether to brush off the rust, apply rust convertor and apply bu brush some black caliper paint. Is this a sensible approach? Any Views?

Phil

[Ron Kwas]

Phil;

I didn't go through all the links, not because I'm done learning (I don't think I will ever be!), but because I have done a lot of Drum removals myself, from falling off easy, to mega-force required, and everything in between, plus read many threads that have come up on the subject, I feel I am somewhat qualified to give some advice, so have collected it here: https://www.sw-em.com/Brake_Drum_Notes.htm

Sorry about the pain and suffering which comes with a mushroomed halfshaft, but that was unnecessary...as was tearing apart your hydraulic puller...more learning experiences there...

My advice is to rebuild the Adjusters with graphite bearing anti-seize, to prevent the galvanic corrosion which is pre-programmed because of the construction in dissimilar metals. My practice and advice is to also grind away the Wear-Lip which forms on the Drum-edge, and to apply the slightest film of AS on the tapered halfshaft during assembly...yes I know that is against standard machinists rules for tapered joints, but living in the real world has taught me to sometimes modify theoretical with practical experience...and considering the wide range of installation force which can be encountered (due to the variation in cotter-pin hole to castellated Nut alignment) that the hubs need to periodically be removed (unstretched!) for service, I wish to spare the halfshafts being subjected multiple times, to mega-force often necessary with a dryfit...so that is my personal practice and recommendation.

I now blast and paint Calipers and Drums in high temp paint...they look a lot nicer, and material which will rust and look like hell today, particularly on drums, is material-loss by which Drums will not get thinner in service, which is a (if admittedly only minor) consideration!

You'll have to make a decision on the delaminating friction material...without seeing it in person, I can't...just know that shoes are not terribly expensive, so erring on the side of caution is advised.

Cheers

[fishyboy]

hi all,
All seem to be going quite well until I manged to snap the NSR brake pipe when trying to undo the connection with the wheel cylinder, which I needed to replace. Just ordered a pair of rear brake pipes.
Phil

[fishyboy]

Hi All,
Quick up date.
Hubs have been cleaned and painted.
Brake levers have been attached to new shoes with M8 bolts and lock nuts.
Got new brake pipe clamps to place cable ties.
Braked adjuster clean up.

New wheel cylinders, spring kit and all ready to go.

Then yesterday I tried to bend the OSR brake pipe and managed to complete mess it up. Beyond use. Being a Friday and wanting to get the brakes sorted this weekend I jumped in the daily and drove to Automec for a second set of pipes.

Hopefully I might get to bend the new pipes tomorrow.

I wish I was a better mechanic!

Phil

[Derek UK]

A cheap tube bender will make you a better mechanic.

[fishyboy]

Derek,
It was the cheap pipe bender that caused the problem (and of course myself). It was a US Pro with metal jaws (picture 1) that nicked the pipe on a tight bend. Got one with plastic jaws from Automec (picture 2) that works much better.

Probably still need something better.

Still not entirely happy with the result but getting there (photo 3).

Phil

[Derek UK]

I'm not a fan of copper pipes. I guess you got a kit from Automec. I Prefer Kunifer, cupro-nickel, as used generally now by most manufacturers inc Volvo and would have chosen that option from them. It bends well. Copper can be unpredictable as it work hardens, which makes it brittle. It also kinks easily.
Looking at Automec prices, they seem to be rather expensive now to what I remember.

[simon roberts]

Should already have some in your inventory ,Derek😜

[Derek UK]

Good memory Si. Yes I do still have the part copper kit you let me have. Can you remember what the kit was then? About £49?

[simon roberts]

Er,no Derek.......I was in my very early 40's then....👍