Odd braking problem

[rbonnett]

This is on the SIII 88". I have not had any brake issues with this truck before. Other than adjusting about a month ago I've not done more than look at the fluid in the reservoir. No softness or pedal pumping, no pulling. Just a little squeal from time to time when its really wet out.

This morning I made roughly 50 mile trip for some shopping. parked the truck, spent a couple hours in the shops, came back to head home. When I pulled out of my parking space, the brake pedal went all the way down and there was barely any braking to be had. Pumping did nothing to improve it.

I checked the reservoir - still full. No signs of leaking at the wheels or other junctions I could get at readily. No puddles or stains on the ground where I was or back in my parking space. Checked the vacuum line to the servo - well connected and no obvious cracks or splits.

At this point I was thinking maybe the servo itself or the master cylinder had given up the ghost. Whatever it was, it looked like the Rover was getting a ride home. here's where things got weird...

I had to back up to put it back into a parking space before I called the tow. So I'm creeping back, ready to yank the parking brake handle, and the brakes worked just fine! I backed up some more - same thing. So I got bold and crept forward - brakes are now working fine.

I drove around in the parking garage for about 15 minutes with no braking problems at all. In the end I drove home the back way so I could avoid anything over 40 mph. By the time I got home I had almost forgotten that there was ever a problem.

Tomorrow I'll check the adjustment and keep an eye out for any out of round or unevenness in adjusting the shoes. If the weather is better than they say I may also have time to pull the drums and see if anything seems funky.

Has anyone seen something like this before? Any thoughts about specific problems this could be pointing me to? Unless something seems amiss, I don't want to start repairing/replacing things jsut because. On the other hand, I don't want to have the brakes fail in a more serious situation.

advice and comments appreciated as always.

[Andrew IIA]

Sacrifice one chicken.... never mention it again.

Regards, Andrew
'63 SIIA 88" SW

[rbonnett]

Time for brake work

Started adjusting and realized I need some truing done on the brake drums, at least in the front. They bind and release in different spots as I spin the wheels forward; going backwards one gets about a half rev and bumps to a complete stop. The rear seemed OK - I ended up one click tighter on one side, the other is exactly where it was before.

I got the drums off the front. On the side that sticks going back, the lining on the leading shoe is worn unevenly just to the ***** eye. Guess its time to do the brakes - at least the front. At least thre's no oil, fluid etc in there

Couple of questions for the gang:

- Is there a good brake shop in the Portland area to take the drums to for turning? No idea if they can be, but I want someone who knows what they are doing. I was thinking a commercial truck shop might be better for this.

- Given the tales of woe I've seen on here regarding sub-par brake shoes, does there seem to be a more reliable way to go? My gut tells me to go with genuine shoes from RN - but if the ProLine seem good I don't mind saving a few $$$.

[bmohan55]

I used the Pro-line pads from our hosts and they were fine. I got my drums turned at the local Ford truck dealer for $25 each, one was bad so I bought a Pro-line drum from our hosts and it worked well.

[LRMAN]

The machine shop at NAPA in Westbrook should be able to get these turned for you.

Brackett Machine in Westbrook can also do the work(more $$$)

My guess about your braking problem would be that one shoe was out of adjustment somehow and when you pressed on the brake pedal you broke something free to allow the show to move out to the drum. When the pedal returned it sucked in some brake fluid so the next time you pressed on the pedal all was fine again.

[greenmeanie]

Word from the wise is to hold out for Mintex shoes.

[Sputnicker]

I suspect that your master cylinder is starting to fail. A weak/worn seal bypassing is one of the few things that can make the pedal go to the floor and then work fine the next time. It's a fairly common (and dangerous) failure mode. In theory, since you have a tandem master cylinder on a Series III, you should still get some braking from at least two wheels, but if those are out of adjustment you could easily get the minimal braking you describe. The fluid that leaked past the seal may may not be visible since you have the tandem master cylinder with servo attached.

It's a lot of work, but I would replace or rebuild (if the bores are smooth) the master and rebuild the servo while I had it out.

[rbonnett]

It figures...

I suspect that your master cylinder is starting to fail. A weak/worn seal bypassing is one of the few things that can make the pedal go to the floor and then work fine the next time. It's a fairly common (and dangerous) failure mode. In theory, since you have a tandem master cylinder on a Series III, you should still get some braking from at least two wheels, but if those are out of adjustment you could easily get the minimal braking you describe. The fluid that leaked past the seal may may not be visible since you have the tandem master cylinder with servo attached.

It's a lot of work, but I would replace or rebuild (if the bores are smooth) the master and rebuild the servo while I had it out.

I had thought the MC would either die and stay dead, or gradually sicken and die. Never would have suspected an intermittent problem.

It all makes sense now: we are finally getting some summer here, I was looking forward to rolling up the canvas and driving. Maybe I've been too smug about my brakes and the Rover gods decided I need smiting.

[DADAMS]

Turning Drums

I just had my drums turned at the machine shop at NAPA in Westbrook... $15 a piece and they seem just fine. I had trouble with new pads and new drums binding. Things spin pretty much freely now.

[rbonnett]

I'm surprised it stopped at all

The things you uncover when you start fixing things.

Neither top spring was installed properly. One wasn't even a top spring - the left front had 2 lower springs, the one at the top hooked using the holes in the shoes. The right hand one was hooked to the post on the backing plate and the hole on the leading shoe.

One of the rubber covers on the left wheel cylinder was split in half and the inside was packed with grit. Luckily I have a new wheel cylinder on hand. I'm amazed it wasn't leaking like a sieve.

I was happy with the rear since they adjusted so nice and easy. Guess they'll have to come apart now too so I can check everything. Yes, I should have done that in the first place. Live and re-learn