Pinion mounted disk handbrake opinions

[HumberSS]

Hey all, so on my camper build (see 4v Dyna camper build thread) i need to figure out the handbrake situation. The original one was mounted to the rear of the gearbox, as is often done in trucks. It was quite small (10" tops diameter)but obvs benefits from the diff ratio for mechanical advantage so doesnt need to be much. I cant mount anything on the back of my auto box so am going to go with a disk mounted on the diff pinion. Spoke to my cert guy today, hes ok with it. Just said make it as big a disk as possible. I can prob safely have a disk about 12" diameter, however the caliper situation is the thing. Ive looked at mechanical types like trojan ones but dont think they will like that for cert, really want sometjing off a car or light truck etc - any thoughts on suitable  mechanically actuated disk calipers appreciated. Any other thoughts also welcome.

[h4nd]

I just ordered a servo controller which may probably drive an electric handbrake caliper, per later (small?) car stuff. It might give you more parts choice, positioning options? 

[flyingbrick]

Lots of cars have cable hand brakes- there should be a huge number of choices.

[johnny.race]

10 hours ago, HumberSS said:

Hey all, so on my camper build (see 4v Dyna camper build thread) i need to figure out the handbrake situation. The original one was mounted to the rear of the gearbox, as is often done in trucks. It was quite small (10" tops diameter)but obvs benefits from the diff ratio for mechanical advantage so doesnt need to be much. I cant mount anything on the back of my auto box so am going to go with a disk mounted on the diff pinion. Spoke to my cert guy today, hes ok with it. Just said make it as big a disk as possible. I can prob safely have a disk about 12" diameter, however the caliper situation is the thing. Ive looked at mechanical types like trojan ones but dont think they will like that for cert, really want sometjing off a car or light truck etc - any thoughts on suitable  mechanically actuated disk calipers appreciated. Any other thoughts also welcome.

Just my observation ... one challenge when fucking around with disc rotors and calipers that didn't come matched from the factory is compatibility. Things like the available gap width a caliper features ... the caliper mounting bolt holes in the wrong place ... the exit direction of the cable pointing at something/wrong way ect. Just some of the arse biters you can encounter. Question; what's wrong with a mechanical Trojan style caliper that makes you think a certifyer would reject it? They are good enuff for road legal trailer duty. Tell. Have you spoken to one of them and he's knocked the use of a Trojan back?  

[flyingbrick]

Wilwood does cable and electronic parking brake calipers.

[smokin'joe]

just thunked about this.... why disc ?
reason i ask is debris failure, as in rock/stone either smashing disc, or getting jammed in caliper, as mounting i 90 degrees from usual fitment.

would a drum be such a cumbersome thing, as most mid-commercials used drum on back of transmission

[Transom]

Little truck handbrake disc system - Nissan condor uses disc handbrake and the caliper is just basicly 2 long bars  of steel with brake pad holders - pivot at one end and handbrake cable squeezes the two onto the disc - spring retracts - about as simple as it gets 

[cletus]

Have seen someone use an oem rear caliper off some sort of car with handbrake mechanism built in as a handbrake caliper

They just sealed up the brake hose port and filled it with brake fluid and used the mechanical handbrake part 

[flyingbrick]

2 hours ago, cletus said:

Have seen someone use an oem rear caliper off some sort of car with handbrake mechanism built in as a handbrake caliper

They just sealed up the brake hose port and filled it with brake fluid and used the mechanical handbrake part 

My brain can't figure out how the piston moves If it's hydrolocked 

[Nominal]

43 minutes ago, flyingbrick said:

My brain can't figure out how the piston moves If it's hydrolocked 

Usually the mechanical mechanism moves a different part, not the hydraulic piston?

[flyingbrick]

I don't know if that system is usual. The ones I have seen have a lever and screw that operates on the same piston as the fluid.

[ThePog]

When we built that caravan we got a kit from one of the trailer places in chch, the calipers were surprisingly nice cnc'd parts and not that expensive. Could be an option.

[HumberSS]

20 hours ago, h4nd said:

I just ordered a servo controller which may probably drive an electric handbrake caliper, per later (small?) car stuff. It might give you more parts choice, positioning options? 

Think i just want a simple mechanical setup,thanks though.

[HumberSS]

9 hours ago, smokin'joe said:

just thunked about this.... why disc ?
reason i ask is debris failure, as in rock/stone either smashing disc, or getting jammed in caliper, as mounting i 90 degrees from usual fitment.

would a drum be such a cumbersome thing, as most mid-commercials used drum on back of transmission

Prob is, it seems easy but the drum actually essentially has a drivshaft spiggot built into it in the factory setups. In order to then put this at the back id need a much bigger drum to accomodate the nose of the diff pinion. While typing this, maybe it is doable though... i did think about the potential for dosk damage. Will ponder more and look at some drums for inspo..

[HumberSS]

5 hours ago, flyingbrick said:

My brain can't figure out how the piston moves If it's hydrolocked 

Thought about this too, either pack the cylinder with grease instead of brake fluid or return the circuit back throigh the bleed nipple

[HumberSS]

2 hours ago, ThePog said:

When we built that caravan we got a kit from one of the trailer places in chch, the calipers were surprisingly nice cnc'd parts and not that expensive. Could be an option.

I looked at the cheap trojan ones but thought cert guy may not like these.. perhaps i need to explore further. Can you send me link to caliper you used? Also might explore drum option further..

[keltik]

A few mid 2000s euro things had a separate cable actuated caliper on the rear discs for handbrake duty.  Could maybe repurpose one of those?

[HumberSS]

47 minutes ago, keltik said:

A few mid 2000s euro things had a separate cable actuated caliper on the rear discs for handbrake duty.  Could maybe repurpose one of those?

Oh yeah, any leads on vehicles? 

[johnny.race]

59 minutes ago, HumberSS said:

I looked at the cheap trojan ones but thought cert guy may not like these.. perhaps i need to explore further. Can you send me link to caliper you used? Also might explore drum option further..

I reckon you need to look at those Trojan mechanical ones more closely. The ones @Transom described above are essentially what they are. I know what they look like and I've seen a pic of a setup being sold out of Aus (I think) for the rear of a transfer case on a r151f. It used a caliper that looked similar to the Trojan. The proof of the pudding will be the holding test that's undertaken on a 1:5 gradient. 

[HumberSS]

1 minute ago, johnny.race said:

I reckon you need to look at those Trojan mechanical ones more closely. The ones @Transom described above are essentially what they are. I know what they look like and I've seen a pic of a setup being sold out of Aus (I think) for the rear of a transfer case on a r151f. It used a caliper that looked similar to the Trojan. The proof of the pudding will be the holding test that's undertaken on a 1:5 gradient. 

I think youre right too, its not rocket science, and they are made for stopping a road going vehicle. Its also only a handbrake. I perhaps didnt drill my cert dude hard enough on whether he would accept a trailer caliper. Im going to explore two veins, the disk/trojan caliper vein and the drum vein, because it seems more hearty.