Viano parking brake tight but not holding

[James Ireland]

My W639 parking brake is giving some problems. I had it adjusted a few times over the years by meahcanics but this time, I decided to do it myself as it was quite weak after the last one was done just before Xmas. All I've done is to tighten it via the little adjustable metal wheels which are part of the brake shoe assembly. I've done this, and now the pedal feels much tighter. I thought it would be perfect, but it still doesnt hold so well on a steep hill. I really need to press my foot really hard on it to get it to work. Anyone any ideas? Is it possible I've tightened it too much? could the shoes need replaced? It doesnt really add up. I looked at the shoes and although quite brown looking, they didnt really have much severe rust or anything.

 

[mioba]

Although what you tightened is linked
to the pedal, is this also tightening whatever is connected to the brake shoes.
Could well be some snagging cable needing a lube.

The shoes don't wear down (unless you drive with the parking brake on amd that would be evident from
wear on the holding face) they just hold.

 

[James Ireland]

I am thinking that it may be down to wear on the shoes. For a time, I used to hear some rubbing from the rear and asked a mechanic to check it as I had seen it before where, normally in winter with a lot of muck on the roads, the hand brake seemed to stick a bit. It has to be this because the its all nice and tight now and releases correctly. Its probably a bit of an awkward job to replace the shoes myself..........
Anyone here done it before? Havent found much in terms of videos on the net etc.

 

[LostKiwi]

There are two parts to the adjustment of the parking brake.
The steps are:
Unwind the cable adjustment.
Adjust both sets of rear shoes to the point they just touch the drum then wind back 2-3 clicks. Note the adjuster will be click forward for tighter on one side, click back for tighter on the other.
Readjust the cable to operate the brake on the 3rd or 4th click of the pedal.

Shoes rarely wear as they should only be engaged when the vehicle is stationary.
Whilst not a difficult job to do it's quite fiddly and frustrating at times. Take a photo of how it's assembled before undoing it all.

 

[M80]

If there is rust on part of the inside of the drum the shoes wont be contact enough surface area to be as effective.
Over or under adjustment of the shoes can have the same effect.

Otherwise be sure both pivot points of the lower applicators are free of rust and able to open the shoes.

 

[alexanderfoti]

If all else fails, pull the rear disks. I have seen the pad backing rust, and the handbrake material fall off, leaving only metal to metal contact.

 

[James Ireland]

If there is rust on part of the inside of the drum the shoes wont be contact enough surface area to be as effective.
Over or under adjustment of the shoes can have the same effect.

Otherwise be sure both pivot points of the lower applicators are free of rust and able to open the shoes.

Thanks. I am going to open it all up and give a good clean. Are there any points I could add some lube or grease in order to get the mechanism working a bit better. I think its probably sticking a little, although that might be down to me having tightened the adjusters too much.

 

[James Ireland]

There are two parts to the adjustment of the parking brake.
The steps are:
Unwind the cable adjustment.
Adjust both sets of rear shoes to the point they just touch the drum then wind back 2-3 clicks. Note the adjuster will be click forward for tighter on one side, click back for tighter on the other.
Readjust the cable to operate the brake on the 3rd or 4th click of the pedal.

Shoes rarely wear as they should only be engaged when the vehicle is stationary.
Whilst not a difficult job to do it's quite fiddly and frustrating at times. Take a photo of how it's assembled before undoing it all.

Thanks.

 

[M80]

In the parking brake mechanism within the drum I use graphite from a heavy pencil to the pivot points
Maybe there is a better and thick grease that might have more longevity?

 

[James Ireland]

Finally, I replaced the hand brake shoes and it has made all the difference. It was a bit of a fidgety job with the springs etc but has been worth it. I also cleaned and got some wd40 on the cable actuator underneath the car, where the cable separates out to each rear wheel. This mechanism has become somewhat rusty and may need replaced some time soon. Thanks all for your help.