Small Engines (Lawn Mowers, etc.): Alko 700 with peerless 700 brake problem, dowel pins, drive pulley

Question

Photo   QUESTION: Hi, i have an alko 700 ride on mower and have a problem with the brake on it. The engine drives the pulley directly for the drive belt, with the blades driven on a clutch below. The gearbox is a peerless 700 with a disc brake on the side. The brakes werent working for a long time, so i have tightened the bolt that has reduced the slack on the transmission. Now i cant get the mower to run freely, and brake properly. What happens with the drive is that the belt tensioner pushes on the belt to supply drive when the pedal is pushed. When it is let off, the tensioner releases a lever is pushed by the tensioner returning, which pushes on the brakes on the transmission.Now the pulley on the transmission is locked as the transmission is braked, and the drive pulley from the engine is still turning. The belt tries to turn as it still has a little tension without the tensioner on it, but isnt turning at the gearbox pulley. It screetches and overheats the engine. The belt is old, worn slightly on the outside so i can't check the no's. I measured it and it is the same length as a standard one is, but has been on for ages and wont have tightened. I have had the transmission out and bolted it back in, and there is no way to adjust the distance between the pulleys. Before it wouldn't brake as it did when it was new, now it tries to brake but the drive pulley is still trying to turn a braked gearbox pulley? I don't understand how this is meant to work, especially with a little tension with the belt tensioner not pushing on. I was wondering if the gearbox should brake the gearbox pulley too when the disc is braked? I took the gearbox apart and it looks like it.  Any thoughts on to fix this problem, and get the ride on to stop properly? Many thanks, allan

ANSWER: First, start with the brake.  You need to remove the assembly and the two dowel pins.  DO NOT loose the rectangular metal plate on the pin side of the assembly.

Dis-assembly and clean the pins with a wirebrush.  They should be shiny and smooth when cleaned.  Next clean the inside holes.  I use some steelwool wrapped around a drill bit to clean the inside of the holes.  

Re-assemble and lightly grease the dowel pins with some white grease so they move easy and don't rust.  Adjust brake.

Let me know if the pins were rusty.

Eric

---------- FOLLOW-UP ----------

QUESTION: Hi eric, thanks for the response. I have already taken the brake off as i got some gearbox grease on it, so i cleaned it up and used a wire brush on the disc surface and pads. The 2 pins were moving freely and not rusted, and were greased when i put them in. I adjusted the mechanism and it seems to stop it fine now, the problem is as the brake is on, it brakes the gearbox pulley. I am not sure if this is right, as the drive pulley is still pulling the belt when the tensioner isnt on (when the brakes are on). Thanks, allan

Answer
When the brake is on it will stop the transmission pulley if the transmission is in gear.  In neutral, with the parking brake set, the input pulley can turn.


Have you recently replaced any of the belts, pulleys, or any other drive parts?

Eric