Ideas for stripped master cylinder reservoir screw?

[QwikKota]

Need to remove the reservoir to clean out the gunk before I can flush lines. The head stripped off the cross bolt/screw that holds it to the master. I have a replacement screw. No real room to drill a hole in the head of the screw for an extractor. What are my options?

 

[Wild one]

Syringe with some vinyl tubing stuck on it,will usually suck most of the crap out,if not unbolt the master cylinder and then you have lots of room to work on it.

 

[Fast69Mopar]

Need to remove the reservoir to clean out the gunk before I can flush lines. The head stripped off the cross bolt/screw that holds it to the master. I have a replacement screw. No real room to drill a hole in the head of the screw for an extractor. What are my options?

View attachment 564739

Why don't you just remove the master cylinder from the brake booster? Remove the two brake lines and the two nuts from the master cylinder and remove it so you can extract the stripped screw.

If you don't want to introduce air in to the brake system you have some room to maneuver the master cylinder with the lines connected. You may have enough room to gain access to the screw to extract it.

 

[QwikKota]

Yeah, trying not to get air in the system. I sucked out as much fluid as I could with a large syringe and did that twice with new fluid. Still has some gunk in there I don't want getting into the system, mainly the ABS accumulator.

 

[QwikKota]

I was able to get a small hole drilled in the screw and an extractor in there but it's not deep enough to get a good bite. The extractor puts a small amount of torque on the screw but slips. That dang thing is hard as a rock but easily stripped when I previously tried to remove it. Makes no sense. I've tried high speed steel and cobalt bits.

I have a spare master cylinder with reservoir off eBay but the reservoir and sensor look slightly different. If they looked identical I would just cut off the plastic lugs from the bottom of the reservoir then I could get a pair of vice grips on the screw shank. 68000908AB

 

[Wild one]

I was able to get a small hole drilled in the screw and an extractor in there but it's not deep enough to get a good bite. The extractor puts a small amount of torque on the screw but slips. That dang thing is hard as a rock but easily stripped when I previously tried to remove it. Makes no sense. I've tried high speed steel and cobalt bits.

I have a spare master cylinder with reservoir off eBay but the reservoir and sensor look slightly different. If they looked identical I would just cut off the plastic lugs from the bottom of the reservoir then I could get a pair of vice grips on the screw shank. 68000908AB

Unbolt the master cylinder and remove it so you can work on it on a bench,you're gonna f u b a r it if you keep trying to mess with it still installed in the truck,you're gonna have to bleed the brakes when done,but that's cheaper then screwing up the master cylinder

 

[Sherman Bird]

Why don't you just remove the master cylinder from the brake booster? Remove the two brake lines and the two nuts from the master cylinder and remove it so you can extract the stripped screw.

If you don't want to introduce air in to the brake system you have some room to maneuver the master cylinder with the lines connected. You may have enough room to gain access to the screw to extract it.

Wow! And maybe go around the block to talk to the next door neighbor! (LOL just kiddin')

Why not just buy a new master cylinder? That being said, leave the reservoir on and douche it with brake cleaner after removal and invert the doggoned thing. I'm pretty sure Red from the "Red Green" show can introduce a way to use duct tape! Just kidding again!

 

[QwikKota]

I was able to drill a pretty deep hole with a left hand drill bit but the extractor still slipped before the screw turned even with a good initial bite. I am trying to avoid removing the master cylinder. The used one I bought has the same sensor after I took a closer look. I will probably cut the lugs off the bottom of the one installed and should be able to get the screw out from the exposed shank.

 

[crackerjack1957]

If you get the hole to big in diameter with drill bit.......the extractor pushes the threads together & locks making it impossible to screw out that way.

 

[Burla]

Keep topping off and blow everything through the lines.

 

[TJP440]

I hate extractors especially smaller ones. you are likely dealing with metal to aluminum galvanic corrosion/seizing.
Your best bet may be to drill and re-tap or replace as mentioned. in some cases slightly tightening before trying to loosen can help but be careful not to go too far or you will have the same result. When reassembling use the appropriate anti-seize compound for the next guy as it might be you
PS: if there is that much gunk in the bottom of the cylinder the seals / bore likely have issues as well. I say REPLACE

 

[QwikKota]

Thanks for the replies. I will wait until the weather cools off a little more and remove the old reservoir by cutting the plastic lugs off. I wouldn't say the gunk was terrible I just didn't want to push it downstream where it could get in an ABS accumulator or whatever it is called. I definitely use anti-seize on steel and aluminum interfaces. Highly doubt the factory does.

 

[QwikKota]

Lugs came off easily with a hacksaw. The screw was really stuck and required some heat and vice grips. The junkyard (eBay) reservoir's level sensor did not latch properly to the connector and trying to remove the old one from the original reservoir was not fruitful. I will just keep an eye on it, not that critical. Seems like some sort of float that closes the circuit on the sensor when fluid is full.