Spongy brakes (1 Viewer)

[fordoford]

After a full day wheeling at Uwharrie with no problems, I was driving on the gravel road back to the campsite, and I snapped the last hard brake line before the caliper (photo below).

I made it back to the site, and the next day I put on a new line and after bleeding all the brakes twice through they still felt spongy. I ended up driving home and it did pretty well, but the brakes did get softer as time went on.

I know it’s sucking in air somewhere, but does anyone know where it might be? The master cylinder is relatively new (replaced around 2 years ago), and there’s no brake fluid leaking, as I didn’t lose any over the hour and a half long drive.

Here’s an extra bonus pick of some flex on Dickie Bell I thought was cool

 

[NC LX]

did you just bleed at that one wheel or did you Did you bleed at each wheel and LSPV? Any time air is introduced into the system, it may be a good idea to start at the Passenger Rear and work your way towards the Drivers front.

 

[roadstr6]

Cool pic. It wouldn't be sucking air. It would leak fluid before it sucked air. You just didn't get the brakes bled enough. You probably have a bubble in the ABS unit. Bleed both fronts again. Do a panic stop on gravel to actuate the ABS. Re-bleed the fronts. Repeat if necessary, but you should be good.

I personally wouldn't mess with the rears or the LSPV. It's a separate circuit from the front, but BOTH fronts need to be bled for sure.

 

[izzyandsue]

You probably still have air in the system. Bleeding it alone may not be enough, may need to flush it further

 

[GLTHFJ60]

All the leaks have been fixed? If there's no leak, then there's no air getting sucked in.

What bleeding procedure are you using? IMO, sounds like you need to take your time and bleed properly at home, not rushing at the campsite.

 

[izzyandsue]

By the way, a quick field repair would have been to kink that hose, the rubber one, or the metal one to limit the fluid leak and air coming in.

 

[roadstr6]

By the way, a quick field repair would have been to kink that hose, the rubber one, or the metal one to limit the fluid leak and air coming in.

Good point, Izzy. I even use this technique when I do brake work at home in the shop. Pinch the rubber line shut with mini vise grips closest to the point that you will be opening the system prior to cracking it open. Doing so stops the flow, reduces mess and prevents excess air intrusion. It makes bleeding afterwards much easier when there's not a ton of air all the way up to the MC.

Seeing @fordoford 's pic makes me wonder why the hard line snapped. I wonder if the soft line from the axle up to the frame may be not be long enough due to the lift and the resulting up and down tugging of the soft line at the lower mount might have created a weak point in the hard line? @fordoford Were longer soft lines installed when your truck was lifted? If not, you need them. The one pictured looks like the factory length to me. To check, lift the front of the truck by the frame until the suspension is at full droop and check the tension on the soft line from the frame to the axle. There should be no tension on it. If there is, you need extended brake lines now, not later. Check is the same for the rear as well.

 

[fordoford]

By the way, a quick field repair would have been to kink that hose, the rubber one, or the metal one to limit the fluid leak and air coming in.

We thought about that after we had already bought the new line, but I’ll definitely remember that for the future.

@roadstr6 Im not sure whether or not the soft line is longer than factory but it doesn’t look like it’d be too short u see full flex. Also , the brakes were fine up until the gravel road, after I hadn’t flexed the suspension for a while. I’ll definitely check it out to see if it needs to be lengthened though.

We bled the front passenger first because that’s what we replaced. Went until it was spitting only fluid. Then went from the rear passenger up to front driver twice and only got liquid on the last run through. We didn’t really rush it because I needed to drive home and we wanted to make sure it was safe. I’ll try stopping on gravel and then bleeding it again tonight. What’s the LSPV? I haven’t heard of it so we probably didn’t bleed it

 

[roadstr6]

Load sensing proportioning valve.