Can the caliper slide pins be pulled out and the helper springs installed while the spring/parking brakes are engaged?
Don't know for sure since I have never tried, but If you were to remove one slide pin at a time, I don't see why it wouldn't work as most of the tension should be parallel with the slide pin. If anything it might be slightly harder to pull out. You could give it a try and see if it will pull out. If it doesn't then you can use the bolt to release the tension on the ebrake. I don't think damage will occur if you try unless you really gorilla out the slide pin with ebrake still on.
No, you will need to release the tension on the parking brake. You can cage the spring brake with the "bolt" or simply chock the wheels that are on the ground and start the coach build air pressure and release the brake.
Thanks jbeem and bbeane for your replies. I was hoping to avoid the additional work of caging the spring brakes. It is not that hard, but it is extra work I was hoping to avoid.
I would not be comfortable working on the brakes with the springs held open by air pressure. Though it is unlikely, the spring could release at an inopportune time and result in injury to the underpaid mechanic....(that would be me). :)) I will take the time and effort to do it safely.
I reversed my helper springs when I installed them backwards without releasing the brakes.
helper springs (https://www.foreforums.com/index.php?topic=31008.msg271318#msg271318)
I would vote no on working on the brakes with the parking brake engaged. If the parking brake is helping to keep the coach from rolling, it would be hard to remove the pins, and unsafe as well. The coach may start to roll, even if you only do one side at a time.
Just chock the wheels if you want more safety. You are going to have the wheel off, so that brake isn't holding anything.
Yes, I will definitely chock all of the remaining wheels that are one the ground and agree that the has wheel off anyhow to remove the pin. Unless there are compelling reasons to not try sliding one pin out and inserting the spring, then I am going to give it a try while the spring brake is engaged. If the pin is tight, then I will cage the spring.
Look at my post on installing the springs. By tapping the pin in about a 1/4" you will free it up. then use a deep socket that the inside diameter clears the pin and install a bolt and washer through the socket and just pull the pin out.
The Meritor maintenance manual suggests using a slide hammer to remove pins. That is what they used at MOT when they did our brakes.
See page 6: http://beamalarm.com/foretravel-links/PDF/brakes-maintenance-manual-mm4m.pdf
If you have a slide hammer, it is no doubt a nice way to remove them, but craneman's approach using a 3/8" bolt also works. I used his approach for inspiration when I removed the pins to do the axle seal replacement. Instead of a bolt and socket he uses so draw out the pin, I just used a 2ft piece of 3/8" all thread. I had intended to use a large socket as the slide weight to make a "poorboy" slide hammer, but did not have to. The pins were not stuck. I was able to just pull them out using the threaded rod. Since I was doing a seal replacement, I removed the top pin to roll the caliper out of the way.
If the pins are stuck, driving them in a 1/4" as craneman suggested should free them up.
I have one but either way removes the pin if you free it up first. My next servicing will include measuring the inside dia. of the pin bushings. With a lathe you can make remover and installer tools out of round stock without emptying the bank account for R&R of the bushings.
When I removed my pins to replace the pads, I used a socket that was smaller than the diameter of the pin and a pry bar to push out the pins from behind. Once I got it out about 1/4 of the way, it easily pulled out by hand from the front. Would have been nice to use a slide hammer, but didn't have one and didn't want to buy one for one set of brakes on one wheel. If I were putting helper springs on all the slide pins then I would definitely get a slide hammer as it would speed things up considerably.
That can work, but there is a risk of "mushrooming" the pin. If you are going to do this, better to use a brass drift which is softer than the pin.
I still like the slide hammer or homemade puller (all thread and deep socket/proper diameter pipe).
I'm curious to see if the pins can be removed with the brake set.
Likely depends on whether the coach is being held in place by the brakes (would move if brake released) or not.
Said another way, whether the pins are under a side load or not loaded.
Blocking wheels and then setting the brake would be the more likely to succeed, but still not as probable as brakes released and coach safely blocked.
Once the wheels are off the ground...and removed, will that not remove any side load?
I hope to try this weekend and will report back. Coach will definitely be safely blocked to prevent movement.
If I encounter any resistance pulling the pin, I will cage the springs.
Just how important are the helper Springs? I like the idea, but my mechanic doesn't. I might need to have someone else install them.
Tom,
What is your mechanic's reasoning behind not wanting them? The brake manufacturer came out with them to address exactly the thing that takes out the majority of the brakes on coaches. The "lazy side" fails to release-- usually caused by lack of exercising the brakes. Not an issue for OTR vehicles or those used frequently.
He says the pads are supposed to touch the rotors, albeit gently.
Sure doesn't take much air pressure on the brake cans to overcome those small springs.
I cannot see any downside to using them other that they lighten your pocket by $20 per set.
I would not do the job just to install the springs, but if you are servicing the brakes, seems like installing them is low risk.
If I was doing a complete brake job, I would definitely put on the helper springs for the peace of mind. However, if you move frequently, you don't need them. Sitting for long periods is the reason the brake pins lockup. Except in winter, I usually move around every 1 or 2 weeks, so I don't think I need them but will put them on someday when I have to redo all the brakes.
I just did all my pin's. Left the shop compressor hooked up to the coach (with drier on air line), chocked the coach, and did the front 1st, then the rear. I simply released the park brake. Didn't cage the rear can.
I took a simple piece of flat stock 1/4" metal, with a hole in it, and a long 3/8" bolt. Made my own slide hammer, all though none of my pins were stuck bad.
I did replace a couple of pins, that probably didn't need it. Replaced the rear pads that were needed. Just drop the top pin out, rotate the caliper down to change things.
* Note, I had the coach raised all the way up also, before I removed the tires. I had to lower it a tad, to let the rear calipers down, because the air hose was too short.
Cheers
Chris
I was able to slide out both pins and install the helper springs while the spring brakes were engaged. The bottom one was a little tight but got it started with a few light taps from the back with a brass hammer. The top one slid out easily.
Well that question has been answered. Good to know the pins can be removed with the brakes set.