1983 Series 3 LWB Brake Issue

[psupe13]

I've replaced most of the brake system on my LWB Series 3 except for the master cylinder and booster. I've been able to bleed the breaks and get only fluid at each of the wheels. However, I still don't have a firm pedal. I've tried all of the tricks I know and all of the tricks I've seen online and I'm not getting anywhere. I'm thinking there might be an issue with my master cylinder. When I press on the pedal I can hear a wooshing sound and there is a little squirt of what I think is fluid that shoots up inside the front of the master cylinder reservoir. Is this typical? I don't think any air got into the master cylinder when I replaced the other components. I was able to keep the reservoir full the entire time.

I've searched the forum and haven't found anything specifically related to my question. Any insight you can provide would be appreciated.

Thanks!

[slowmo]

You may have installed the upper springs on the brake shoes incorrectly (everyone does the first time). Do NOT connect the spring to both shoes. There is a post on the backing plate for one end of the spring and the other end attaches to the opposite shoe. If you search "brake springs" you will have enough reading to keep you busy for a while. I probably went through several hundred gallons of brake fluid thinking I was not getting a good bleed before someone set me straight.

The deal is if you attach the spring to both shoes, the shoes have too great a travel to contact the drum with one pedal application, so you have to pump it up a couple of times. It has the same feel as air in the system, but it isn't. It's another design "feature" unique to Rovers AFAIK.

[psupe13]

Thanks for the reply. I'll definitely check the spring settings out. I took a bunch or pictures before taking the shoes off originally, so I'm sure I put them on the same way, but that doesn't mean they weren't wrong to begin with.

I forgot to include in my original post that the master cylinder has Girling 74660213.2.0100 cast into the side of it.

[mearstrae]

If you have fluid bubbling inside the master cyl.,without fluid loss, it's most likely that the seals are gone inside the master. If you don't have a dual master cyl. now's the time to install one. If that or re-building is beyond your ability (or tool box), just pick up a re-built master and call it good.

'99 Disco II
'95 R.R.C. Lwb (Gone...)
'76 Series III Hybrid 109
'70 Rover 3500S

[cnfowler]

Rebuilding a MC is a difficulty of 1 on a scale of 1-10. No special tools required.

If the MC has bad seals, you may have a booster full of brake fluid. That was the case with mine. Definitely worth pulling the MC to check.

As far as bleeding, have you tried reverse bleeding? The idea of reverse bleeding is pushing the air in the direction it wants to travel - up. Normal bleeding tries to push the air down to the wheel cylinder. Also, have you loosened each fitting in the brake lines to release any air that may have been trapped at the fittings?


Colin

[ninescorpions]

You may have installed the upper springs on the brake shoes incorrectly (everyone does the first time). Do NOT connect the spring to both shoes. There is a post on the backing plate for one end of the spring and the other end attaches to the opposite shoe. If you search "brake springs" you will have enough reading to keep you busy for a while. I probably went through several hundred gallons of brake fluid thinking I was not getting a good bleed before someone set me straight.

The deal is if you attach the spring to both shoes, the shoes have too great a travel to contact the drum with one pedal application, so you have to pump it up a couple of times. It has the same feel as air in the system, but it isn't. It's another design "feature" unique to Rovers AFAIK.

Boom. This is exactly what is wrong with my brakes. I also was having a weak pedal until I pumped it three or four times. I honestly I did not know yet what was causing my problem. But I have the LF hub off working on the bearings, so after reading this I went out and took a look. Sure enough, the shop that initially worked on my Rover attached the upper spring to both shoes. The distance is also great than if you connected to the backing plate, so the "hook" on the spring is not where it should be. I have not put it back together, but I would bet a cold frosty one that once I fix that on all four corners, I get a firm pedal. If not, then I will drink the cold frosty one and head back to the drawing board.

Thanks so much for this tip!

[psupe13]

I was able to spend some time in the garage yesterday and tried some of the ideas you guys suggested. I inspected the shoes and springs (all OK) and opened up the connections to release any air. I again tried reverse bleeding the system and had the same soft pedal and fluid spurts in the master cylinder. Afterwards I used a pressure bleeder to bleed the system with no change. I didn't have time to get the master cylinder off, but I plan to do that this weekend. If there's nothing wrong there I'll be thoroughly stumped.

Thanks again for all your advice.