1999 Nissan Vanette/Cargo (also Serena) handbrake lacking power

Irish Steve

1999 Vanette, the back brakes were relined, and new cylinders fitted last year, and after that, it passed the DOE, albeit that the handbrake was not great, but it was above the limit.

This year, it was clear that there was an issue with the handbrake, it was struggling to hold the vehicle on a relatively benign hill, despite significant pressure being applied to the handbrake lever.

So, closer investigation. The handbrake cables were not great, due to water penetration, so they were replaced, and the handbrake set up again, it was coming on at the first notch, and going solid at about 4 notches, but still not really good on the hill, despite not doing many miles since the reline etc last year.

Closer investigation with 2 of us, and the drums off, which had to be done with care, to avoid parts flying at great speed in all directions. The findings were interesting, hence this post, in case someone else gets caught with the same issue.

With the drums off, it was possible to see what was happening to the shoes, and we found that on the third notch, the rear shoe was kicking out of alignment with the drum, and we had to look very closely to see why that was happening.

Turned out to be a manufacturing defect in the (spurious) brake shoes, the lever that the handbrake cable connects into has a 90 degree bend at the bottom that the cable connects in to, and for reasons that escape us, the offset piece had a significant extension beyond the end of the cable slot, and it was too long, so the shoe was binding against the backplate when the cable pulled the lever forward. There is a recess in the backplate that was allowing everything to fit correctly when the brake was off, and when new, it didn't need to travel beyond the recess, but once slightly worn, there was no longer enough travel in the lever to actuate the handbrake sufficiently.

The solution was to remove about 3 mm of steel from the end of the lever, which then allows it to move further forward when the handbrake is pulled, and the result is a test pass.

I don't know how many vehicles this could apply to, the vanette/Cargo and Serena all share the same shoes, but there might be others affected.

It was a strange issue to find, in that there's no view of the shoes when the drum is in place, and with the drum on, the shoe wasn't able to kick out in the same way, so the handbrake went tight without applying the correct force to the shoe and drum.

Hopefully, with the way that things like search engines work, posting this here may save someone else from the pain of finding this obscure fault.

jca

Well done to track it down, so satisfying to pull that lever and feel the wheels locking tight. I can't quite visualise the setup but I'm certain that someone struggling with the same problem knows exactly what you mean. Fair play.

Irish Steve

Thanks, everyone I've spoken to since we found it has not had similar experience, and they were surprised that it's happened. There's a rubber bump stop mounted in the back plate that can be pushed from outside to check if the lever has returned to the home position, so the recess is to allow space for fitting that, which meant the lever had about half an inch of free movement before the oversize part caught on the backplate. With the drum off, pulling further caused the shoe to twist to clear the obstruction, but with the drum on, the shoe couldn't twist in the same way, which meant that only the edge of the shoe was in contact with the drum, and the lever couldn't move further forward, so the shoe was not making good contact with the drum, and it also then meant that the leading shoe didn't make full contact with the drum either, so very reduced brake effort, which only fully shows up on the rolling road test, or if you find a reasonable hill and then push the handbrake when stopped by reversing and seeing if it holds, which before we found the fault, it would not.

It's the first time on over 40 years I've come across a fault like it, and while I'm not a full time mechanic, I've spent a lot of time around a wide range of vehicles over that time, and the full time people at the workshop I was at had not seen it either.

Unfortunately, while I know where the shoes came from, I don't know the manufacturer, otherwise I'd feed it back to the supplier as it for sure had us scratching our heads. I couldn't photo or video the thing, between the backplate and the shoes, it was very hard to actually see what was happening, and I HATE bad youtube videos so I wasn't about to add to the numbers of them!