[briansmack]

Hi everyone, regarding your Beringer Brakes:

-Do your Beringer brakes "drag" on the rotors? ie the calipers/pads are always left with some residual contact on the discs. For example, I can jack either wheel up off the ground, give a hard of spin as possible by hand, and I will only get 1/4 to 1/2 of a wheel rotation. I can even remove the brake line and fitting from the calipers to prove out the notion of any residual pressure being left in the lines somehow and get the same results. This is also evident with brand new pads, or thin pads just about at the end of their wear limits. For another visual, if you slightly rock the plane back-fourth, the rotor stays clamped by the caliper, and the wheel "notches" and small metal contact tabs clunk against the rotor ears.

Calipers, pistons, seals, fluid, etc all previously verified & replaced with Beringer in working the issue, but same results.


In addition, has anyone had problems with brake shudder? As bulletproof as Beringers are built to be, I previously observed both rotors to be slightly warped. Beringer replaced them, problem resolved for a few months, and has since returned. I fear in part it could be to above issue of constant heating/drag.

thanks

 

[lr172]

Hi everyone, regarding your Beringer Brakes:

-Do your Beringer brakes "drag" on the rotors? ie the calipers/pads are always left with some residual contact on the discs. For example, I can jack either wheel up off the ground, give a hard of spin as possible by hand, and I will only get 1/4 to 1/2 of a wheel rotation. I can even remove the brake line and fitting from the calipers to prove out the notion of any residual pressure being left in the lines somehow and get the same results. This is also evident with brand new pads, or thin pads just about at the end of their wear limits. For another visual, if you slightly rock the plane back-fourth, the rotor stays clamped by the caliper, and the wheel "notches" and small metal contact tabs clunk against the rotor ears.

Calipers, pistons, seals, fluid, etc all previously verified & replaced with Beringer in working the issue, but same results.


In addition, has anyone had problems with brake shudder? As bulletproof as Beringers are built to be, I previously observed both rotors to be slightly warped. Beringer replaced them, problem resolved for a few months, and has since returned. I fear in part it could be to above issue of constant heating/drag.

thanks

suggest that something is wrong in the MC. The valving should be opened in the released position. So, as you start rolling the wheels, the rotor will push back the pads to leave a small clearance between pad and rotor and you get only a very slight resistance from the pads with the wheel spinning. If you push the plane 5 or 10 feet and the brakes are still applying a meaningfull resistance to rolling, I would argue that something is not right with the valves in the MC or, less likely, that the piston is hanging up in the calipar bore (not common except for knicks or other mfg flaws). Constant pressure, even moderate, on the pads is going to create a LOT of heat, so no surprise that the rotors keep warping. Do you have a parking brake valve? If so, the issue could also be in that device. Never seen a berringer setup, but know that sometimes on the matco MC, that the spring is not strong enough to fully push the MC piston into the released position and get dragging pads.

 

[wirejock]

Beringer

It drags when lifted and spun? One side or both?
One side I would favor a cylinder but two seems unlikely.
Is the pad wear even or uneven? Also I would favor the cylinder(s). Drag will also heat the rotors and potentially cause warpage.
Also check the Anti-Lock valve if equipped.
Beringer Master Cylinders have a return spring so my money is on one of the other two. Parking Brake valve or Anti-Lock valve. Especially if the problem is on both wheels.
Just my old guy automotive opinion.

 

[Walt]

Guess nobody read what you said, if you've removed the hyd lines from the calipers then that eliminates anything on the hyd side. Sounds like an installation issue of some sort, I've installed a set of Beringers on an RV7 with no issues. What you're experiencing is definitely not normal, wheel should spin freely.

 

[dmattmul]

Wheel friction

As others have stated the wheels should spin fairly easy. Just replaced my tires and wheels (425 hrs. they wore very evenly inside and outside pad left and right) I'm sure you have checked but Beringer makes 2 assemblies for the RV series 5-inch tires (And another for the 10's mains 6 in). Part numbers EA-002N(A) and EA-002.2N. From what I can tell the parts are very close just the thicknesses different. If you would have a mismatch the pads could rub. Just a long shot but worth checking. If you don't have the maintenance manual go on-line. Beringers pic inserts do not have very good resolution. You did safety wire the brake disc? If the contacts slots are moving in the "inserts" sounds like the 1 mm (~0.041) safety wire might not be secured. This keeps the tabs from moving in and out. Are inside and outside pads wearing evenly? RV-?

 

[dmattmul]

Spin test

Since I’ve never did a “spin test” and since the wheel pants were still off decided to go out to the hangar and give it a try. Although the wheels felt pretty easy to rotate by hand and the plane seems to roll even easier now thought all was ok. I did try the test and was a little surprised I can only get about 1 to 1.25 rotations when I spin them. Both wheels rotate about the same amount. I’m going to put the wheel pants back on and fly it. Hopefully no surprises but we’ll see.

 

[Swiss14A]

We hang our aircraft and always have a little drag. It is negligible if weight is on and the aircraft is in movement, but from spinning a wheel by hand, it stops as you said, after half rotation or so. Or friend in the same hangar has the same o his cleveland and my former vari eze was also the same. IMHO it‘s normal and no need for concern…

 

[dmattmul]

How much "spin"

This is from the Beringer 5 and 6 in Maintenance manual.

 

[briansmack]

Thanks all for the feedback...kind of mixed results. while the manual notes and in theory everyone wants our brakes not to be dragging, it seemed those that went and physically checked seemed to have the same results that I do, that there is residual drag or very slight clamping force left.

I dont have a parking brake, only 1 set of master cylinders, tried with and without the AILR, different reservoirs, new brake lines, calipers etc. Just seems the caliper pistons are fairly stiff in their design and sealing and dont "relax" much at all after pressure is relieved.

Still disappointing on a 2nd set of rotors to develop brake shudder.

 

[briansmack]

Hi everyone - I should have done this originally - but I uploaded a video to show the amount of drag on the wheels.
-the rocking/knocking is just showing how the disc is held stationary and the wheel rocks the clips against the disc "teeth"
-this is trying to rotate the wheel pretty hard by hand and represents how much they always drag
-as discussed above...I can literally disconnect the brake lines right off the calipers and it has no impact...there is no residual pressure...the caliper pucks just have no give, or dont relax at all.

I'm still at a loss for this - and convinced its warping rotors and wasting brake life. I had even changed out all components with Beringer for same results.

Yes you will notice not an RV gear leg but your forums are invaluable with the amount of people viewing with similar setups.

 

[Little Wing]

I have Beringers here as well and get 3/4 to one revolution spun hard by hand.
Are you running DOT or mineral? I have found with dot fluid pistons tend to stick a bit on mountain bike disc brakes unless kept clean. I run mineral on the Beringers.

 

[dmattmul]

I have been using DOT4 for the last 5 years and have not added a drop to my reservoir. I believe that is what Beringer recommends. If there are documents that state otherwise let me know. Great brakes!

Thanks

 

[Walt]

I have been using DOT4 for the last 5 years and have not added a drop to my reservoir. I believe that is what Beringer recommends. If there are documents that state otherwise let me know. Great brakes!

Thanks

There should have been a sticker of some sort on your cylinders, but you might want to double check that, Dot 4 was typically only used in light sport, their aviation (real airplanes) recommends the following:

In the ”mineral” or “MIL” family we recommend using the MIL-PRF-87257 as a replacement of the MIL-H-5606. These 2 fluids
are compatible and miscible with each other. MIL-PRF-87257 is fire resistant and synthetic-hydrocarbon based, it has also a higher boiling
point than MIL-H-5606.

NBR (Nitrile) seals → mineral fluid → red color → MIL-PRF-87257 recommended
EPDM seals → DOT4 brake fluid → colorless to amber color → DOT4 only

From the MM I have:
4.3 Brake Fluid
Brake fluid required by the new brakes is per MIL-PRF-87257. The sticker on the fluid reservoir must be replaced by the new one delivered in the kit.
CAUTION: Standard MIL-H-5606 Brake fluid is replaced by fire resistant fluid:
MIL-PRF-87257, make sure that only this brake fluid is used.

 

[chaskuss]

Hi everyone, regarding your Beringer Brakes:

-Do your Beringer brakes "drag" on the rotors? ie the calipers/pads are always left with some residual contact on the discs. For example, I can jack either wheel up off the ground, give a hard of spin as possible by hand, and I will only get 1/4 to 1/2 of a wheel rotation. I can even remove the brake line and fitting from the calipers to prove out the notion of any residual pressure being left in the lines somehow and get the same results. This is also evident with brand new pads, or thin pads just about at the end of their wear limits. For another visual, if you slightly rock the plane back-fourth, the rotor stays clamped by the caliper, and the wheel "notches" and small metal contact tabs clunk against the rotor ears.

Calipers, pistons, seals, fluid, etc all previously verified & replaced with Beringer in working the issue, but same results.


In addition, has anyone had problems with brake shudder? As bulletproof as Beringers are built to be, I previously observed both rotors to be slightly warped. Beringer replaced them, problem resolved for a few months, and has since returned. I fear in part it could be to above issue of constant heating/drag.

thanks

Dumb question time. Does the Beringer system use tapered roller bearings? If so, the issue may be as simple as loose wheel bearings. You may need to Snug up the axle nut to remove any play. Play in the bearings will cause the wheel tire and rotor to be off-center compared to the caliper. That can cause drag which will overheat the rotors.

 

[Walt]

Dumb question time. Does the Beringer system use tapered roller bearings? If so, the issue may be as simple as loose wheel bearings. You may need to Snug up the axle nut to remove any play. Play in the bearings will cause the wheel tire and rotor to be off-center compared to the caliper. That can cause drag which will overheat the rotors.

They use sealed ball bearing with a fixed caliper and floating brake disc.

 

[dmattmul]

There should have been a sticker of some sort on your cylinders, but you might want to double check that, Dot 4 was typically only used in light sport, their aviation (real airplanes) recommends the following:

In the ”mineral” or “MIL” family we recommend using the MIL-PRF-87257 as a replacement of the MIL-H-5606. These 2 fluids
are compatible and miscible with each other. MIL-PRF-87257 is fire resistant and synthetic-hydrocarbon based, it has also a higher boiling
point than MIL-H-5606.

NBR (Nitrile) seals → mineral fluid → red color → MIL-PRF-87257 recommended
EPDM seals → DOT4 brake fluid → colorless to amber color → DOT4 only

From the MM I have:
4.3 Brake Fluid
Brake fluid required by the new brakes is per MIL-PRF-87257. The sticker on the fluid reservoir must be replaced by the new one delivered in the kit.
CAUTION: Standard MIL-H-5606 Brake fluid is replaced by fire resistant fluid:
MIL-PRF-87257, make sure that only this brake fluid is used.

Walt, you are 100% correct and Beringer marks the caliber with the correct fluid one should use. Some Beringer brakes use DOT4, and others use MIL-PRF-87257 with DOT4 being used predominately as you mentioned in light sport aircraft but dependent on the seal used. I guess it's a good thing I never needed to top off the reservoir. Thanks !

 

[chaskuss]

Walt, you are 100% correct and Beringer marks the caliber with the correct fluid one should use. Some Beringer brakes use DOT4, and others use MIL-PRF-87257 with DOT4 being used predominately as you mentioned in light sport aircraft but dependent on the seal used. I guess it's a good thing I never needed to top off the reservoir. Thanks !

Is it possible that you were supplied with one caliper that has EPDM seals in it? Using the mineral oil based Hydraulic fluid would cause that seal to swell. A swollen seal with also prevent the piston in the caliper from retracting normally.

 

[dmattmul]

Is it possible that you were supplied with one caliper that has EPDM seals in it? Using the mineral oil based Hydraulic fluid would cause that seal to swell. A swollen seal with also prevent the piston in the caliper from retracting normally.

My pistons retract normally and wheel spins per spec.

 

[chaskuss]

My pistons retract normally and wheel spins per spec.

In that case I would suspect that the issue is in the master cylinder. Check to make sure that the rudder pedal and that master cylinder are not binding preventing the piston in the master cylinder from retracting completely

 

[dmattmul]

In that case I would suspect that the issue is in the master cylinder. Check to make sure that the rudder pedal and that master cylinder are not binding preventing the piston in the master cylinder from retracting completely

Sorry, STOP.....I don't have an issue, and never had one, PLEASE read thread.