| | | Crazy mods by frscke1 - December 02nd 2023 8:18 pm
| | |  1990 B-250 Brake Drag | Joined: Jun 2019 Posts: 23 Likes: 9 stranger | OP stranger Joined: Jun 2019 Posts: 23 Likes: 9 | Hey y’all,
After spending several months sitting while doing bodywork, I finally got my van reassembled and ready for a summer road trip. However, the night before leaving I was running some last minute errands and noticed a bit of drag from the passenger front wheel, by the time I pulled over to check, smoke was spewing from the wheelwell. Oh well, better that then to discover the problem on the highway.
Now that I’m back it’s time to figure out what’s up. Pulling the front passenger wheel I found the brake cylinder covered in burnt leaking fluid, so I replaced the caliper. The fluid that drained from the old caliper looked like pale hot chocolate. It felt like there was a bit of grit in the wheel bearings, so I replaced those too while things were apart.
After reassembly and bleeding, I found that when the brake pedal’s released, the brake doesn’t immediately disengage, it still drags for a bit. I jacked up the driver side to see if it had the same problem, and yeah, it also drags after releasing the brake, worse than the passenger side. The caliper looked pretty nasty, so I replaced it in case it was bad, but it didn’t help much, the brakes are still slow to release.
I haven’t replaced the brake lines yet, I’m concerned that if they’re both dragging, maybe the problem is further upstream. So rather than replace more parts, I figure I should take a step back and diagnose as much as I can.
I haven’t checked the rear brakes yet to see if it effects all four wheels, but I’ll try that next. Any ideas? Contamination in the master cylinder or combination valve? Something else? Any suggestions are appreciated. Thanks in advance! | | |  Re: 1990 B-250 Brake Drag | Joined: Jun 2019 Posts: 23 Likes: 9 stranger | OP stranger Joined: Jun 2019 Posts: 23 Likes: 9 | After pouring over the manual and watching a lot of youtube, I returned to the shop this afternoon to see what else I can figure out. The service manual suggests troubleshooting the combination valve and master cylinder by watching the valve stem extend and retract with braking. It retracts fine, so that's one less thing to worry about. A clog preventing fluid returning to the master cylinder should also prevent the stem from returning, so the contamination should be downstream of the valve I guess? ![[Linked Image from live.staticflickr.com]](https://live.staticflickr.com/65535/53098395969_016f080b73_h.jpg) I haven't checked operation of the brake booster, since the problem's occurring while the engine is off. But I'll probably check that too, just in case. I jacked up the back end to check the rear wheels, and they release just fine. I considered that the booster push rod depth might be adjusted too far out, pre-loading the master cylinder. But since the back wheels spin freely, and the fronts will begin to loosen with time, that seems unlikely. Since it affected both sides, I assumed it wasn't hoses, but it's probably hoses. The front left hose is coming from Vancouver, so there will be no progress until later this week. Bonus photo, an old caliper full of hot chocolate. Yum. A very thorough fluid change is in order once these hoses are installed. The next real challenge will be freeing up the ABS bleeder screw, it's good and seized. ![[Linked Image from live.staticflickr.com]](https://live.staticflickr.com/65535/53098216626_deceb6ab41_h.jpg) | | |  Re: 1990 B-250 Brake Drag | Joined: Nov 2013 Posts: 2,140 Likes: 111 veteran | veteran Joined: Nov 2013 Posts: 2,140 Likes: 111 | After pouring over the manual and watching a lot of youtube, I returned to the shop this afternoon to see what else I can figure out. The service manual suggests troubleshooting the combination valve and master cylinder by watching the valve stem extend and retract with braking. It retracts fine, so that's one less thing to worry about. A clog preventing fluid returning to the master cylinder should also prevent the stem from returning, so the contamination should be downstream of the valve I guess? ![[Linked Image from live.staticflickr.com]](https://live.staticflickr.com/65535/53098395969_016f080b73_h.jpg) I haven't checked operation of the brake booster, since the problem's occurring while the engine is off. But I'll probably check that too, just in case. I jacked up the back end to check the rear wheels, and they release just fine. I considered that the booster push rod depth might be adjusted too far out, pre-loading the master cylinder. But since the back wheels spin freely, and the fronts will begin to loosen with time, that seems unlikely. Since it affected both sides, I assumed it wasn't hoses, but it's probably hoses. The front left hose is coming from Vancouver, so there will be no progress until later this week. Bonus photo, an old caliper full of hot chocolate. Yum. A very thorough fluid change is in order once these hoses are installed. The next real challenge will be freeing up the ABS bleeder screw, it's good and seized. ![[Linked Image from live.staticflickr.com]](https://live.staticflickr.com/65535/53098216626_deceb6ab41_h.jpg) My Dodge B250 passenger side hangs up/drags. Intermittent. I think it's from all the dirt. But we've received a lot of rain on the South Plains, Huge Boomer thunderstorm just last night. That should lube it up some more! Really though, you're on it! Good job and good wrenching chasing that down!
BBC Blue 1990 Chevy G30 L19 7.4 EXT Church Van, maternity division DogVan 1988 Dodge B250 LA series 318 Wedge 5.2 TBI A500 Cabin Cruiser '94 Dodge B350 www.xplorermotorhome.com/Xplorer MH model 230 230 hp LA series 360 Wedge MPI 5.9 A518 OD auto Old vans are getting pricey! | | |  Re: 1990 B-250 Brake Drag | Joined: Jun 2019 Posts: 23 Likes: 9 stranger | OP stranger Joined: Jun 2019 Posts: 23 Likes: 9 | Thanks Wedgy!
Man, talk about a rabbit hole. While I was checking the rear brakes, I noticed I'm due for new pads and drums, and the parking brake cables could stand to be changed too. But I'll focus on one project at a time and leave those for a couple weeks.
The hoses were a real project, I'll make a separate post to How-to (Dodge) in case it helps someone.
I don't know if it's the hoses or the fluid flush, but it appears I've solved my brake drag issue. I'll take it for a spin tomorrow and see how it goes. | | |
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