Brake Bleeder Screws Leaking Fluid From Threads

[Daddy O]

Hi,

I have the stock F5 supplied brakes and have just installed and bled them. Noticed a couple days ago the bleed screws are seeping fluid from the threads on both the RF and RR calipers. It's not a lot but if I wipe them dry, they are damp after about an hour and will eventually make a drip overnight. I have tried loosening and tightening, using some 1000 grit to polish the seating ends as well as buying replacement bleeders, no luck, the new bleeders even leaked worse. The replacements were Dorman units that did not seem very high quality though. Anybody else run into this? I did a search but did not see anything. Really don't want to have to replace both calipers but I don't know what else to try.

Thanks for any insight you can offer.

[JohnK]

I had an issue recently where my hydraulic clutch bleeder was weeping, similar to what you describe. No amount of tightening would get it to stop leaking. Upon inspection, it was evident that the threads had been damaged and little shards of metal had been pushed down where the taper is. No chance that was going to seal that way. In my case the fix was easy - new bleeder assembly. In your case, I'd inspect the calipers carefully to see if there's any foreign matter around the tapered surface that would prevent the bleeder from sealing properly. Perhaps a small dental pick or similar might be able to clear the debris so the bleeder can seal.

Here's a photo of the new and old bleeder in my case, showing the problem.

https://thefactoryfiveforum.com/attachment.php?attachmentid=153475&d=1631911549

[Railroad]

You might cut some slots in the face of a bleeder screw and see if it will clean the mating surface when tightened and loosened. The more slots the better and making a clean cut with probably a cut off wheel in a dremel tool.
Naturally the bleeder screw will no longer be of use.
If you want to really get into it, grind the threads off the bleeder screw and after adding the cut slots, spin it in the hole.
good luck,

[Daddy O]

Thanks guys, gives me some things to consider.

[mikeinatlanta]

https://www.napaonline.com/en/p/UP_BF17?cid=paidsearch_shopping_dcoe_google&store=25063&campaign=GSC-Brakes&campaign_id=8659198719&adgroup_id=106304766654&adtype=pla&gclid=CjwKCAjwzOqKBhAWEiwArQGwaLXItvDYL-EwdhFCOJfUkbVvAfWLbMcid43wMgveFYcFGHjRP9CuHBoCDtkQ AvD_BwE&gclsrc=aw.ds&

[bobl]

Copper flair washer.

[AC Bill]

When building my roadster, I found that there was an issue with some new bleeder screws I'd purchased, bottoming out in the caliper before they were tightened fully. They felt tight of course but they weren't sealing. I compared them to the bleed screws on the old calipers, and figured out I needed to use some with less thread length.

For example, both are the same thread size, but their lengths vary.

3/8-24 Short Bleeder Screw, 1.25" overall length

3/8-24 Long Bleeder Screw, 1.5" overall length

Some of the variances can be seen here.
https://www.pegasusautoracing.com/group.asp?GroupID=BLEEDER

[J R Jones]

You might cut some slots in the face of a bleeder screw and see if it will clean the mating surface when tightened and loosened. The more slots the better and making a clean cut with probably a cut off wheel in a dremel tool.
Naturally the bleeder screw will no longer be of use.
If you want to really get into it, grind the threads off the bleeder screw and after adding the cut slots, spin it in the hole.
good luck,

RR, The concept is valid but in cast iron, difficult and with deep surface flaws unlikely.
Bleeders and seats are at 90 degrees. A drill bit is 70 degrees. If you or a machinist can sharpen drill bits by hand, you might try grinding a drill bit to 90 degrees and with a light touch, one might recondition a bleeder seat.
jim