Sticking Trailer Brakes

[wise one]

I have a tandom axle trailer with electric over hydraulic brakes.

The brakes work well, but I find that periodically the brake calipers do not "release" the brakes.

The calipers are single piston style with twin brake pads.

The piston seem relutant to release pressure.

I always hose the trailer down after each use with "Salt-Away" mixed with the water and I only dunk the trailer to the level of the rear axle (trying to keep as much of the mechanics out of the salt as possible!)

Yet the last brake to stick was actually one of the front wheels which stays out of the water when I launch the boat.

I've tried cleaning the pistons, giving them a light spray of grease or lanolin and WD40 but I still get the periodic problem.

When the problem occurs, quite often it will "fix" itself after launching the boat (the sudden reduction in tempartute freeing up the piston?)

Any ideas / guidance would be appreciated.

Thanks

Edited January 22, 2009 by wise one

[warnie]

Wise one

In regards to the piston you make mention is it a stainless steel piston????????

I experienced similar to what you described in my existing Trojan calipers where the pistons were made of a

bakelite I sourced alternative pistons made out of stainless steel (and are quite cheap to purchase)

and replaced with them and all has been good now for three years..

It's also advisable to activate your brakes on the trailer weekly whilst parked at home particularly in the off

season when it tends to get less usage........ experiance as shown me regardless of what you do to try and

minimise the effect saltwater does to brakes with hosing etc........in actual fact does very little good it only

makes one feel better with themselves

regular maintenence to the brakes and calipers is the go!!!!!!!!

Cheers Warnie

Edited January 22, 2009 by ungry warnie

[Geoff]

The brakes work well, but I find that periodically the brake calipers do not "release" the brakes.

Are you saying , both sides at the same time or one side releases & the other does not.

If both sides at the same time then the problem is not with the caliper but in the hydraulic system , perhaps around the master cylinder or the hose going to the splitter.

Have you checked the hydrolic lines for blockages. It is not uncommon over a period of time for a blockage to occur there by preventing the oil pressure to drop . Remove the hoses & blow out with compressed air

I've tried cleaning the pistons, giving them a light spray of grease or lanolin and WD40 but I still get the periodic problem.

To lubricate the O ring & inside the cone use only special brake grease which is available from most automotive spare parts stores

The use of any other lubricants will cause the O ring to swell up & the piston to seize.

Seeing you have been using non brake grease it may be wise to replace to O rings around the pistons

Geoff

Edited January 22, 2009 by Geoff

[wise one]

The brakes work well, but I find that periodically the brake calipers do not "release" the brakes.

Are you saying , both sides at the same time or one side releases & the other does not.

If both sides at the same time then the problem is not with the caliper but in the hydraulic system , perhaps around the master cylinder or the hose going to the splitter.

Have you checked the hydrolic lines for blockages. It is not uncommon over a period of time for a blockage to occur there by preventing the oil pressure to drop . Remove the hoses & blow out with compressed air

I've tried cleaning the pistons, giving them a light spray of grease or lanolin and WD40 but I still get the periodic problem.

To lubricate the O ring & inside the cone use only special brake grease which is available from most automotive spare parts stores

The use of any other lubricants will cause the O ring to swell up & the piston to seize.

Seeing you have been using non brake grease it may be wise to replace to O rings around the pistons

Geoff

Its only one brake at a time - so it is in the calipers.

I'll take a look at the "O" rings next time one ceases and I take it apart.

Thanks guys!

[pelican]

The small tin backing plates on the back of some pads can loose their spring very quickly in salt water or get grit behing them so they seat unevenly and then allow the pad to rub slightly. You can buy trogan pads with a stainless backing.

Some cheaper pads swell slightly with water immersion and perform badly so have a look at texture and measure them up now and at next maintainanace.

I have mistaken dragging pads for what was actually the rust line outsideand inside the pad contact area on the disc actually causing the drag noise when left for long periods. Warped disc will give same impression.sometimes so check it is spinning true on it's bearings.

Wih some axels I have seen different brands of bearings fitted ( or failing bearings or new) and the hub with disc will sit 1/8 of an inch in or out from original and since caliper has never worn on that area or is outside it's float range it constantly rubs. Have you changed a bearing on that axel or it well worn?

Bleed them as it can be a case with air in the line or caliper

Check and maintain the pins the floating disc floats on and ensure the rubber seal caps haven't let water in.

The pins or bolts that hole the pads in can get a texture on them from corrosion ( only slight ) and it can cause enough resistance so they rub and don't return all the way smoothly especially if left on when parked as they create a tiny ridge ( corrosion or a wear point). Inspect them or if you want to rule it out switch to other caliper and see if problem moves.

We have also put larger springs in boosters on PBR vacume units to get a better return so they can cope with a bit of wear, sticking over the years and still function perfectly but not sure of the internals on the electro hydraulic units and their return method but distributer may have a upgraded return spring for 4 and 6 wheel applications?

Just ideas you have probably looked at most

Edited January 22, 2009 by pelican