Trojan Brakes with Hydrastar System

G'day all,

I've got dual axle Mackay trailer, about 6 years old. Been great until a couple of weeks ago when the brake calipers started locking on to the discs. Got very hot on a short trip home.

I've replaced the pads, freed and greased the slide pins and did the bearings while the wheels were off. Bled the hydraulics, all good.

Took it for a spin around the block today and two of the discs / hubs are still getting hot. They never have before. 

Are there any gurus North of the river that can fault find these? I've gone as far as I can with it. 

Thanks for any tips! 




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Blackgold's picture

Posts: 47

Date Joined: 11/06/15

 Sounds like  pistons could

Sun, 2020-10-11 19:49

 Sounds like  pistons could be seized

Posts: 502

Date Joined: 28/11/16

I agree. Pistons probably not

Sun, 2020-10-11 19:57

I agree. Pistons probably not retracting after braking  

Livewire's picture

Posts: 149

Date Joined: 25/11/16

Me too. Gives me the shits

Sun, 2020-10-11 20:01

Me too. Gives me the shits can't get any consistency out of my breaks hydrostar with dual discs . Been serviced every year still f---cked. I've been told an up grade to stainless clippers would fix it but would like to hear from people who have tried. 

Scotte's picture

Posts: 1103

Date Joined: 07/12/06

Me too livewire.

Sun, 2020-10-11 20:15

Looks like a pretty expensive exercise with all stainless calipers, pistons, pads etc. And I'm not even sure that would stop all issues. 

I also would love to hear from anyone who have all stainless  for a few years and can recommend them.

Stevo81's picture

Posts: 1249

Date Joined: 16/04/12

 I stepped up to a stainless

Mon, 2020-10-12 19:24

 I stepped up to a stainless setup on my new trailer after putting up with ongoing issues on my last rig. 5 years now and no dramas at all. Use Redarc a Tow Pro Elite & it brakes perfectly. I wash my boat & trailer/brakes with pressure washer & snow cannon after most uses 

Boat gets used a shitload so never sits around for too long either 


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Scotte's picture

Posts: 1103

Date Joined: 07/12/06

 Ok cheers,5 years is good.

Mon, 2020-10-12 21:19

 Ok cheers,5 years is good. just out of curiosity what brand calipers did you go with 

Scotte's picture

Posts: 1103

Date Joined: 07/12/06

 Ok cheers,5 years is good.

Mon, 2020-10-12 21:19

 Ok cheers,5 years is good. just out of curiosity what brand calipers did you go with 

Scotte's picture

Posts: 1103

Date Joined: 07/12/06

 Certainly sounds like

Sun, 2020-10-11 20:08

 Certainly sounds like pistons.

You've done well to get 6 years out of them.

I've got alko brakes that are 15 months old and have had issues with 2 of the  4 calipers,  first on being the slides and second one had a sized piston. Compressor couldn't even blow it out. Ended up servicing all 4 calipers which i will not do again.

 the  stuck one I finally got it out with a pilot bearing puller.

Not sure the price on trojan calipers but I'd seriously consider replacing them. Not worth buying pistons and seals when you can possibly buy new ones complete with pads and turn it into a swap out job, unless you have the stainless ones with all stainless pistons and pads

Scotte's picture

Posts: 1103

Date Joined: 07/12/06

 other thing to check is that

Sun, 2020-10-11 20:24

 other thing to check is that the pins aren't bent or aren't sitting parallel and bind up on the carrier. 

Posts: 150

Date Joined: 08/03/09

Swap out job for my UFP calipers

Mon, 2020-10-12 06:45

I have found it is easier to order a new set of four calipers complete with pads etc from the US.  Cost is about $100-$125 each US, get delivered to your door.  You might even be able to find them in Australia at a reasonable price now, but last time I ordered them they wanted $300 each in Australia.  Same for the hydrastar unit, 3 years ago it was AUD660 ex USA, AUD1200 in Australia.  You swap them out and then when you have some time salvage the old ones for spares.  You can also order new stainless pins, as I found they were the cause of some of my brakes seizing.  With new brakes there is less chance of stuff ups and also gives you more confidence when towing a long distance.

ranmar850's picture

Posts: 2643

Date Joined: 12/08/12

I have stainless calipers and steel discs.

Mon, 2020-10-12 07:44

 Can't remember the brand , fitted new by Easytow as an option. Only just over 2 and a half years, not long I know, but no problems so far. Plenty of k's in that time. Just regular washing and a set of pads replaced. 

Posts: 315

Date Joined: 10/12/07


Mon, 2020-10-12 07:54

 It will be the pistons for sure. Get a seal kit and re do them. I replaced mine with a composite material. Bakerlite i think it is called. From Perth Brake Parts. I also put stainless slider pins in.  So far so good. Plenty of rubber greese. Brakes are not made to be dipped in salt water and then be left to sit around. There will always be issues. I also give them a good soak with the fresh water hose on the boat after I pull the boat out. That way they dry whilst i drive home. Also give them another good wash at home and then drive around the block manually putting the trailer brakes on. Get a bit of heat in them to help them dry. I also  turn the system off when I back the boat in so they are not activating whilst in the salt water.

Posts: 90

Date Joined: 27/07/16

I do exactly what you do. I

Mon, 2020-10-12 08:18

I do exactly what you do. I turn off the brakes when I get to the ramp and give the trailer a good wash after launching & retrieving the boat. I still use the original 1993 as built Discs and calipers, nothing fancy just early V8 commodore calipers and they work great with the hydrostar 1600psi actuator. Holden must have made a good product back then as the trailer did sit for a few years and when I did a brake service the slider pins and bushes were perfect.

Posts: 787

Date Joined: 09/10/06

 Callipers are a throw away

Mon, 2020-10-12 12:28

 Callipers are a throw away item. 6 years good run.

To test if calipers are releasing,  jack up one side,  spin tyre and have someone pull the breakaway. They should lock up. Now put breakaway back in and spin tyre . You will know if the calipers are sticky. Do this on all tyres. 

For the guys saying just order new Callipers of another brand. not all brake calipers match up to other calipers mounts. Mounts need to match caliper bolts and need welding to suit calipers.

If buying new calipers of any brand. Pre grease before fitting if your mechanicly minded.

peterm8's picture

Posts: 38

Date Joined: 25/10/13

 Thanks all! Sounds like I

Mon, 2020-10-12 21:05

 Thanks all! 

Sounds like I haven't done too badly.  I think I'll go for stainless calipers and pistons. The guys at Easytow reckon it's the best way to have piece if mind. Better bring home some crays this year to keep the better half happy with boat maint costs! 


Ambition and Ability - Don't confuse them!

Livewire's picture

Posts: 149

Date Joined: 25/11/16

 I got a quote today. 4

Mon, 2020-10-12 22:40

 I got a quote today. 4 stainless calipers , pistons , move the mounting brackets to suit pads bearings grease $1500.00 big dollars. 

Posts: 315

Date Joined: 10/12/07

Stainless calipers

Tue, 2020-10-13 06:47

 I am not sure why you would spend all that money on stainless calipers. From what I have seen the caliper is the only part that doesn't rust. The issues come from the piston, slider pins and discs. Replacing the slider pins and pistons seem to have done the job for me. Pretty cheap fix. Not sure if you can get stainless discs but I reckon that would really help.  And give them a big wash and dry each time you go out. Anyway thats what I have done. Did it my self...and I am the least mechanically minded....just got sick of spending more time on the trailer than the boat.