brake pedal has to be pumped up? Then holds firm?

[GeniusAndHisAssistant]

Ebben and I are just about to roll the series IIA out of the shop for its maiden voyage after 30+ years in a barn and then a few thousand $$ in new parts. What a long adventure this has been! We had some issues replacing the entire brake system, which now boasts all new cylinders, lines, drums, pads, everything (well almost). We finally have the brake pressure holding tight (or so it seems) but when you first go to use the pedal it goes to the floor and has to be pumped up about 6 times to work. It holds firm then, but when you let it go again for over 5 seconds or so you are back to square one.

We are not running the motor yet - does this have anything to do with the power assist brakes? Does the engine only have to be running or is there something more involved here. We have NOT replaced the vacuum assist brake assembly.... kind of hoping we wouldn't have to. Funny to hold out hope on saving at least one part!

Any thoughts are welcome and appreciated. What an education this has been for both of us. Can't wait to fire it up in a few days and take it for a spin on the north forty here.... high fives for sure with the young man!!

j & E

[Andrew IIA]

I love this thread/.

[Contractor]

Several thoughts.


You don't mention the Master Cylinder........is it new? Failed seals internally can lead to what you describe.

Adjustment of the shoes..........are you sure they are adjusted properly? Pumping multiple times could indicate an improperly adjusted snail cam. You pump to increase the amount of fluid sent to the wheel cylinders which in turn moves the shoes closer to the drum because there is too much initial travel. Tighten the cams until you can't turn the drum and then back it off one notch at a time until it spins free.

Booster.......it works with vacuum off the manifold. I have found two ways to check for failure based on first hand experience. One is when applying pressure to the pedal with the truck running it wants to stumble. Your diaphragm is likely leaking and you have a vacuum leak causing the truck to stumble......this should be fairly obvious.

Or, you can simply hear it leaking from the pedal box when applying the brakes. Often times you will have a very hard pedal.

Rule that stuff out.

[SafeAirOne]

The booster should have no impact on this problem as described.

I forget, is this an 88 or 109?

If the adjuster cams are correctly set, then you probably need to bleed the brakes more and/or examine the master cylinder for correct function.

[bobzinak]

If the rover you trying to bleed is a 109, you MUST slacken the brake off to minimize the air pocket in the two wheel cylinders on each wheel as you bleed them, I believe this is only true for the 109"s. I know this because one of my friends pumped gallons of brake fluid through his system. I had a copy of the "white bible" that came out long before the famous "green bible" after consulting it and slackening off the wheel cyl, the brakes worked fine. pumping the brakes on any vehicle is not acceptable when your life relies on them to be working properly. I don't think that you have to slacken them all, just the one you are bleeding. adjust brake shoe cams after doing so, and move on to the next wheel. as always start with the on furthest from the maste cyl. if you are having trouble with an 88 try this and see if your problem resolves itself.. I have posted this advice before on this web, and it has solved the problem. also my friend who was having the problem bleedignhis 109 brakes had driven it up a steep grade, parked and tried to bleed it,forward and backward and not been able to remove air from the system..best of luke, post back here if this works..bobzinak "rove on"

[GeniusAndHisAssistant]

The master is new. We set the snail cams at first but left in plenty of slop. I bet that is exactly the problem! We'll reset those now that they have moved around a little. Just by the description of having to pump up to get them started.... that must be it. Very exciting. We'll post some photos when we roll it out. I think also the diaphragm is likely cracked too. So much for not replacing every darn brake part!

Thank you so much again.... I think you nailed the problem when we were stumped (again!).


J&E

[cedryck]

Or there is a possibility of air still trapped in the system, Proper bleeding is essential, before set up of the snail cams, good luck, cheers. Post some pics when you are driving it,,

[bugeye88]

Yep, air in system, either the air pocket described by bobzinak or in line somewhere. Pumping brakes to get a firm pedal is a dead giveaway for air in there.

Bugeye88

[stomper]

I would also take a close look at how the shoe springs are set up on your truck. Rovers are very specific compared to other drum brake set-ups for other cars. The spring attaches to a post, and then to only one of the shoes, where most other drum brakes systems attaches the spring to both shoes. There are several write-ups about this, and pictorals that will walk you through the proper set-up step by step.

Without the proper spring set-up, you will always have a 2 pump brake system. Obviously you have a little more going on right now since you have a 6 pump system, but while you are checking everything, make sure you don't overlook this. This link doesn't have photos, but it does explain the set-up.http://www.roversnorth.com/info/63

[bugeye88]

Right on for the shoe springs Stomper, I'd forgot about that, but did have that situation myself on another series Truck that I bought with that condition.

Rob
Bugeye88

[GeniusAndHisAssistant]

Thank you everyone... issues resolved - we like to think anyways! The snails were not yet set (forgot), and some springs were on incorrectly, and other stuff on backwards too! The link from Stomper (above) was key. Very helpful, as was about every other comment to us on this thread. Thank you again...

We will be rolling and taking some photos soon!

j & e