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dockrocker 06-24-2005 10:30 AM

Trailer brake question
 
I'm new to the whole trailering thing, so please be gentle. ;)

I've got a 1991 Magnum (www.magnumtrailers.com) trailer under my 1996 Powerquest 290. The trailer is steel, dual axle. Believe it has brakes on both axles (not looking at it right now and the ol' memory isn't what it once was...).

I'm 90% sure the brakes are surge brakes, not electric. There is a master cylinder on the trailer, and the tongue of the trailer is made to slide a bit - there is a shock absorber mounted in the tongue - I'm assuming this is what activates the brakes.

First question - after I come to complete stop, and then start to go forward, the trailer makes a serious *THUNK* as the tongue extends to its limit and the trailer actually begins to move. Pretty unnerving, to say the least. Is this normal, and if not, what should I do to correct it?

Second question - how difficult would it be to replace the surge set up with electric over hydraulic? My new 2005 F-250 has the built in trailer brake controller, might as well use it...

Third, the brakes might have some air in the lines. The master cylinder was replaced last year, and when the former owner tried to bleed the brakes he found the fittings on the brakes themselves are stuck in place. Should I just take it to reliable trailer shop in town and have them look at it?

Thanks!

hp500efi 06-24-2005 10:48 AM

Re: Trailer brake question
 

Originally Posted by dockrocker
I'm new to the whole trailering thing, so please be gentle. ;)


I'm 90% sure the brakes are surge brakes, not electric. There is a master cylinder on the trailer, and the tongue of the trailer is made to slide a bit - there is a shock absorber mounted in the tongue - I'm assuming this is what activates the brakes.!

Mike, your assumption sounds right!


First question - after I come to complete stop, and then start to go forward, the trailer makes a serious *THUNK* as the tongue extends to its limit and the trailer actually begins to move. Pretty unnerving, to say the least. Is this normal, and if not, what should I do to correct it?
Mike, yeah that is normal. When you mash the brakes, the momentum of the trailer slides and activates the surge brakes. Does not hurt to once in awhile try that to make sure your surge brakes work. Nothing worse than making a panic stop and finding out the trailer brakes don't work :eek:



Second question - how difficult would it be to replace the surge set up with electric over hydraulic? My new 2005 F-250 has the built in trailer brake controller, might as well use it...
The more electrical you have dipping in the water the more trouble your asking for which is the reason most trailers have surge brakes. I don't mind the surge. I have electric on my toy trailer and they certainly work much better but then again I am not dipping them into the water constantly.


Third, the brakes might have some air in the lines. The master cylinder was replaced last year, and when the former owner tried to bleed the brakes he found the fittings on the brakes themselves are stuck in place. Should I just take it to reliable trailer shop in town and have them look at it?
Bleeding brakes on a surge set up probable needs to be done with some type of machine that activates the fluid movement ... I guess I would take it in to make sure it is done right.

Your truck should pull that beast without breaking a sweat. Makes a huge difference in the tow vehicle as you probably found out right away. Make sure you always leave plenty of space in front of you when towing, make sure the lights work, safety chains, and straps on the boat to trailer are in tact and tight. Happy towing.

dockrocker 06-24-2005 11:15 AM

Re: Trailer brake question
 
Thanks Jeff - biggest thing I've towed prior to this was a dinky two-place, one axle open sled trailer. It didn't even have brakes! :D

I was more worried about the clunking than anything else. The trailer is actually in pretty good shape for being almost 15 years old. Couple spots of rust on the fenders, but other than that it looks good. I haven't towed with the new truck, but the wife's Durango pulled the 290 back to our place from Lansing, about 90 miles, with no problem. Tracked straight and true, no wiggles or sway.

I just want to make sure all is well before we haul the boat over to Grand Haven for Smoke on the Water in July.

ofshore 06-24-2005 11:33 AM

Re: Trailer brake question
 
DR, if the thunk you hear is metal to metal then the actuator is probably missing a hard rubber stop that should be in there, I can feel a slight tug on mine but I can't hear it.

Electric/Hydraulic brakes are a nicer set-up, IMO, and it's easy to switch them over, the hyd. line that goes to your current actuator should screw right into the electric/hyd unit then all you have to do is put a new coupler on the trailer where the old actuator was. The electric/hyd units are around $500-$600.

For bleeding the brakes any automotive store will have a little vacuum bleeder that attaches to the bleeder screw and draws the fluid through the lines and their cheap around 15-20 bucks they work pretty good but you'll have to loosen the screw which needs to be done anyway, if there's air in there the brakes won't work worth a $hit which could be a problem.

dockrocker 06-24-2005 11:38 AM

Re: Trailer brake question
 
I think the bleeders on the brakes are frozen; that's what the guy I bought the boat from told me and he's been pretty straight up on the whole deal. There's a trailer shop by my house, I'm thinking I'll take it by there and have them take a look at it.

The trailer shop guy (TSG) told me that *if* they couldn't get the bleeders unstuck, it would be $40/wheel for new wheel cylinders, plus installation at $55 / hr. Does that sound reasonable? Or is this something a shadetree mechanic could do? I'll admit to being a little nervous, since this is brakes we're talking about... :eek:

rich allen 06-24-2005 11:48 AM

Re: Trailer brake question
 
My guess is that your clunking sound that you are getting when you take off again, can be helped by bleeding your system. If you have air in the system, which it sounds like you think you might, you will get that sound. Some sound is normal, cuz when you take off again you are pulling the tongue back out to its stop again, but alot of clunking means that piston in the master cylinder is traveling a whole lot, and usually is caused by alot of air in the system. Another cause, if the brakes are older, can be the piston and bore having water in them, which causes some corrosion. This prevents the piston from coming back out all the way on its own,( there is a spring inside the bore which pushes it back out),, to get ready for the next braking.Even though your tongue is coming out when you take off, the piston isn't. The master cylinder never has a chance to pump back up, and you will get lots of clunking. They make rebuild kits pretty cheap, if that is the case.

dockrocker 06-24-2005 11:52 AM

Re: Trailer brake question
 
I think it's exactly like Rich described. Guess I'll take it in to this shop and they can at least tell me what it's going to cost...

ofshore 06-24-2005 11:52 AM

Re: Trailer brake question
 
It really shouldn't be that hard to get the bleeder unstuck but it's hard to say without seeing it, you can buy a whole new caliper for $150 and the cylinder should be integrated into the caliper, I don't know what he's replacing for $40, can you take a digital photo? $55/hr probably isn't a terrible shop rate though

http://shop.easternmarine.com/index....categoryID=155

ofshore 06-24-2005 11:54 AM

Re: Trailer brake question
 
Oops, after thinking more (could be dangerous) they could be hydraulic drum brakes then you could replace the master cyl.

RedDog382 06-24-2005 05:01 PM

Re: Trailer brake question
 
Electric over hydraulic is a much better system. No part of the "electric" goes in the water. The hydraulic part is controlled by an electric pump on the tongue of the trailer actuated by a brake controller in the cab of the vehicle.

Surge is OK if they are working properly, but they suck on wet roads ... you have to stop the forward momentum of the truck to engage the trailer brakes. I can't tell you how many times I have slid into the middle of an intersection on wet roads with my old surge brakes and a 311 when the light changed on me.

I think bleeding the system and adjusting the brake shoes correctly will significantly reduce your clunking.

Do you have somewhere you can leave the boat in water overnight? It is MUCH EASIER to work on the brakes without having to slide around on your back underneath the boat. You might be able to get the bleeders loose with a big pair of vice grips after several applications of penetrant like PB Blaster. I would just get all new bleeder valves and replace them. It is easiest to get someone with a power bleeder to do the bleed for you.

dockrocker 06-24-2005 09:52 PM

Re: Trailer brake question
 
I think I'm going to take the trailer in to a local place and have them go through the whole brake system. It might cost me a couple hundred bucks, but at least I'll have some confidence that it was done right, and I can then learn how to do it myself when it's less critical (we're leaving for Smoke on the Water in a couple weeks).

And I have to say the OSO community rocks - not one comment about my obvious trailer ignorance! :D

Outdrive1 06-25-2005 12:43 AM

Re: Trailer brake question
 
If you are taking it in to spend money, you minght as well have them adjust the brakes, replace the bleeder valves and repack your bearings and replace the seals. If they are drums the adjustment is childs play. All this stuff is pretty easy to do yourself, and pretty inexpensive. I would say you really need to bleed the system if he replaced the master without bleeding anything, you can gravity bleed them or buy a pump like mentioned before for a minimal price. He probably never tried to loosen the valves (not easy to reach without jacking the trailer up and removing the tire) and if he did the whole assembly will come out pretty easily with some vice grips.
How do they know you need new wheel cylinders without even looking at it? I would be very surprised if they were bad. You may just need a brake adjustment unless they are discs in wich case you calipers slides may be frozen up. Just take them apart, replace the pads and lube the slides real good. Pads should be about 30 an axle. Seals will be 4 or 5 bucks a wheel. Sounds like they already talked you into a few hundred dollars without even touching it.

RedDog382 06-25-2005 05:17 PM

Re: Trailer brake question
 

Originally Posted by dockrocker
not one comment about my obvious trailer ignorance! :D

I think we've all been there! :D

dockrocker 06-25-2005 10:21 PM

Re: Trailer brake question
 
You guys have shamed me into hauling it home and having a go at it myself, so I expect you jokers to be ready with your helpful advice! :drink:

Outdrive1 06-26-2005 12:21 AM

Re: Trailer brake question
 
OSO will come through for you. :drink:

boatman22 06-26-2005 05:13 AM

Re: Trailer brake question
 
Just replaced my surge brake to Electric/Hyd yesterday, what a difference. Total cost was around $700. but the trailer stops so well it's worth every $. It also is easy to change over, took me the better part of the afternoon. :D :D :D

ofshore 06-26-2005 09:33 AM

Re: Trailer brake question
 

Originally Posted by BADKACHINA
If you are taking it in to spend money, you minght as well have them adjust the brakes, replace the bleeder valves and repack your bearings and replace the seals. .

definitely jack up each side of the trailer and check the bearings. about 6 months after I bought by boat I was backing it into the water and one of the tires floated away :eek: At the time I had never thought of checking the bearings now I check them a few times a year, loosing a tire half way across michigan might just ruin the weekend.

mwdill 06-26-2005 08:39 PM

Re: Trailer brake question
 
had a buddy that had that happen to him on the ramp:eek:

VIPER7 06-27-2005 12:03 AM

Re: Trailer brake question
 
A bad shock in the hydraulic surge coupler and air in the brake system will cause severe banging of the surge coupler when taking off and stopping. I have a triple axle trailer with disc brakes on two axles and when I received the trailer new from the manufacture it had air in the brake system. After I blead the brakes the banging somewhat improved but it still hit pretty hard. I pulled the two shock absorbers out of the surge coupler and checked them as best I could for load required to move them. It appeared to me that they could not be effective as it took only 25 pounds of pressure to close them. I called the coupler manufacturer and they sent me new shocks that stopped most of the banging taking off and all of it stopping. You will still get some if you take off hard without tightening up the slack in the coupler. Good coupler shocks, brakes free of air and functioning, and proper driving techinque for surge brakes allow the hydraulic surge coupler to work very effective without the bad banging.


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