Front passenger wheel locked up

[dn010]

I went to move my car from the driveway into the garage last night, and found that it would not move forward - or rearward for that matter. I thought maybe I had something blocking a wheel but there was nothing under the car, so I gave it a little more and the front passenger tire started to skid. Clearly the brake is locked up on that wheel. Pumped the brakes and it finally released enough to move it into the garage but I could hear the brake was still partly engaged. So, new caliper time.

Has anyone used D-Go's new replacement pairs (not the big upgrade)? https://www.deloreango.com/us/front-calipers.html
Houston wants $300 per caliper rebuilt and I'm not really feelin' that right now.
Of course, I could also rebuild them myself if the stock caliper is superior to anything else available.

[David T]

I went to move my car from the driveway into the garage last night, and found that it would not move forward - or rearward for that matter. I thought maybe I had something blocking a wheel but there was nothing under the car, so I gave it a little more and the front passenger tire started to skid. Clearly the brake is locked up on that wheel. Pumped the brakes and it finally released enough to move it into the garage but I could hear the brake was still partly engaged. So, new caliper time.

Has anyone used D-Go's new replacement pairs (not the big upgrade)? https://www.deloreango.com/us/front-calipers.html
Houston wants $300 per caliper rebuilt and I'm not really feelin' that right now.
Of course, I could also rebuild them myself if the stock caliper is superior to anything else available.

Sounds more like a bad flexible brake hose than a bad caliper but it can be both. It is not that difficult to rebuild the caliper, you need new pistons, dust seals, and an "O" ring. If you want them "pretty" Eastwood sells paint for brake calipers. If you have one bad brake hose, get the kit and replace them all.

[dn010]

The rubber lines from vin 712 are still on there so it is very possible it could be collapsing internally. I do have a new set of DPI's stainless braid lines somewhere, I will install those over the weekend and see if that cures it. I'll probably still buy new pistons and rebuild kits for the fronts only, "while I'm in there".

[Mark D]

Rebuilding the calipers is not difficult. Just a little messy if they are really gunked up. I disassembled and sand blasted mine and had them re-plated in yellow zinc by DMC Midwest. New seal kits are still available from Napa, PN 667 for the front and 989 for the rear.

https://www.napaonline.com/en/p/UP_667

I'd replaced the flexible rubber brake hoses too, those can fail internally and get blocked off and act like a check valve to hold pressure even after releasing the brake pedal.

Some pics from when I rebuilt mine:

https://dmctalk.org/attachment.php?attachmentid=30008&d=1407856735

https://dmctalk.org/attachment.php?attachmentid=26170&d=1395931220

https://dmctalk.org/attachment.php?attachmentid=21846&d=1378704122

https://dmctalk.org/attachment.php?attachmentid=21848&d=1378704133

https://dmctalk.org/attachment.php?attachmentid=26172&d=1395931725

[Helirich]

^ that?s cools.

[Josh]

If budget is your largest constraint, rebuilding your calipers its the best way to get you back up and running. Besides seals, you may need a piston if things are locked up bad.

An option that gives you very affordable calipers and removes your reliance on delorean specific parts is the Miata front brake upgrade.

https://lsdeloreanstore.com/collections/control-arms-and-suspension/products/miata-front-brake-upgrade

[dn010]

Hey Josh,

If going to Miata or the Wilwood setup, do you suggest staying 38:62 or moving to 50:50 for the BMC? I've decided to replace the entire brake system including the MC and booster. They both still work but I just want them replaced so I don't have to deal with it later. I did replace the master cylinder at one point, I just can't remember when, so it is definitely not original. Not even sure where to get a good master these days, DMCH doesn't disclose where theirs are made and D-go says theirs is made in China (!).

And to update, the hose seemed to be the culprit along with the passenger side caliper pistons being seized. The hose, once disconnected at the caliper, would not even drip. The caliper bores were filled with black sludge. They have some pitting but nothing bad at all, so they can still be reused/sold to someone who needs them.

[Josh]

Both the Wildwood and Miata calipers are sized based on the stock 38:62 master.

I do not recommend running the 50:50 master in 99% of situations on these cars.

[dn010]

Thanks man. Just ordered the 38/62 master cylinder. Plan for now is to use the stock, rebuilt calipers so I can still drive the car in/out of the garage while I work on getting the LS4 rebuilt, DOD- and all that other fun stuff as well as getting the parts to complete the wilwood upgrade. Might take me another month or two but when the time comes, I'll be placing a rather hefty order with you. My biggest constraint right now is time to actually work on all this stuff.

[dn010]

Had a chance to pull the master cylinder out last night. Turns out I've been running a Girling 50/50 all along judging by the tag. I cannot remember when this was installed but I have a lot of miles with it. Will be interesting to see how it does with the 38/62 installed.
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[dn010]

Boosters, or servos as in the manual, old vs. new. Old one is still in working condition but it's fugly. The mount, which is in similar condition, will be changed to stainless also. I might clean them up and stick them on ebay, but I'm not sure it's worth the effort.

On the other hand, does anyone have any tips on what to use to clean the inside of the plastic brake fluid reservoir? Not sure what to use that won't melt it. I tried isopropyl alcohol so far and it won't remove the grime on the bottom.

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[Mark D]

Boosters, or servos as in the manual, old vs. new. Old one is still in working condition but it's fugly. The mount, which is in similar condition, will be changed to stainless also. I might clean them up and stick them on ebay, but I'm not sure it's worth the effort.

On the other hand, does anyone have any tips on what to use to clean the inside of the plastic brake fluid reservoir? Not sure what to use that won't melt it. I tried isopropyl alcohol so far and it won't remove the grime on the bottom.

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Throw in a handful of washers, nuts, or small screws, etc. Add alcohol or spray in some brake cleaner and shake it up. The small parts will get into all the nooks and crannies. You can also tear up a magic eraser into small chunks and throw those in there with the screws.

Here's a before and after on mine using that method:

https://dmctalk.org/attachment.php?attachmentid=31954&d=1417637678

https://dmctalk.org/attachment.php?attachmentid=29998&d=1407726839

[dn010]

Was going to try that old trick but I thought the narrow gaps and passageways might be a problem. Not sure if yours looks the same but this is what I'm dealing with:
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Now that I think of it, I do have a bag of some small ball bearings somewhere that I can try, just hope none get stuck. I'll mess with it tomorrow.

In other news, it was a biotch getting the original servo mount out of the car. Apparently there are metal sleeves/spacers that lie between the body sections: section one is where the servo mount is and the other section where the pedal box is, between the two sections is foam and the spacer sleeves. The studs run through the sleeves. The lower stud was seized in the sleeve/spacer. Took an hour to get that removed. The RTV in the area where the clutch master is mounted is shot, so I have to get a tube to get that sealed up. I had to remove the clutch master in order to get the mount out.





Throw in a handful of washers, nuts, or small screws, etc. Add alcohol or spray in some brake cleaner and shake it up. The small parts will get into all the nooks and crannies. You can also tear up a magic eraser into small chunks and throw those in there with the screws.

[dn010]

I'm pretty much done with this project. I ended up tossing the reservoir into the ultrasonic parts cleaner and after 30 minutes it looks new. So I ended up throwing the caliper halves and bolts in there too and after that, into the vibrator/tumbler. Everything cleaned up well, new pads all around, put the stainless braid lines on along with some replacement sections of brake lines that were bent oddly. I bled the MC first, then all wheels. They felt spongy still so I bled them again yesterday and the fluid came out clear with no bubbles, pedal was a bit more solid but it still goes kind of low. When I pump them it gets more solid, so I think I still have air somewhere. I bled them using the old school method of a bottle of fluid attached to the bleeder screw, press the brake down, open the screw, close the screw etc.

While it has been quite some time without driving the car, I don't recall the brake pedal going that low and feeling that spongy, so I want to bleed them again using my power brake bleeder. Anyone know where I can get an adapter for it to fit our reservoirs?

During all this, I noticed my steering column has a lot of play in it. I thought the adjusting knob was loose but it turns out the cage is broken all the way around. So along with power bleeding, I also need to pull the steering column to weld.