The aluminum fitting that attaches to the left side of the brass junction block, the threads are stripped and leaking fluid. I tried to tap it but the aluminum is just too fine of material to do it successfully.
What is the name of the part/part # and where can I source one?
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
The entire valve has to be replaced because the fitting that detaches has bad threads? I do appreciate your reply, but please explain to me why so? The combo valve is discontinued, correct? So I have to find one on Ebay, CL or a junkyard?
Because that fitting is "cap" for the spool. Part of spool goes inside the cap. 1. Aluminum body doesn't have enough metal to take a bigger part. No-one makes such a part. Helicoil won't work. 2. Any misalignment trying to re-thread/fix the cap then spool can bind up.
Call/visit local GM dealers, online GM outlets, or find a used part.
Ok, thank you for the explanation. Just so I am completely clear, the inside (female) threads are stripped where LH brake line screws into the adapter, not the outside threads that thread into the combo valve itself. The reason I asked about the outside (male) threads in the above pic is to see if I could find a fitting to replace just that piece. Not thread the combo valve's internal threads, which is where the spool is located, correct?
I found quite a few on car-parts.com for around $25, there's one for an 87' on Ebay for $35, will an 87' work?
I conferred with Fiero Store about the issue, we determined since just the female end of the adapter is damaged, not the male that fits in the spool of the combination valve, that replacing the fitting should suffice in repair.
One thing of note, I did notice when I started to bleed the system, thus discovering the leak at the brake line/adapter fitting, that no fluid made it to the back lines when I cracked open the bleed valve. Is this because of the leak and air in the system?
I did see a few post where the combination valve gets stuck preventing fluid from circulating within the system. Seems I recall people leaving the key in the position with the brake sensor attached to release the locked valve?
Any help would greatly be appreciated as my retired neighbor wants to buy the car and has far more time/resources to devote to it than I do at this time. I really need to get it back on the road as soon as possible.
Part numbers are in my cave. You didn't say year of your car.
Repairing brake parts means You're hoping "repaired" part doesn't leak or blow out and cause brakes to fail. When that happens, New Owner or his Estate can sue you. Repair Problems could be now, soon or worse during driving.
"Fiero Store said..." Just how to they think you are going to fix the combi valve?
Normal Brake Line Pressure is 500-1800 PSI. This thread sees fluid pressure directly, unlike line nuts. That pressure will find any repair defects.
Brake Fluid will eat many things. Some fast while others take a few days, including Many Epoxies, Permatex thread locking/repair products, etc.
Use a Helicoil? TIME-SERT insert? Have you ask the maker? Insert kits cost money and any type could have problems for this application. Valve body size could be an issue. Remember that brake parts HATE Oil/grease.
Yes, Some people have binding combi valve for various reasons. Most are corroded from old fluid. 1 symptom is Manual resetting the spool. Normally Spool will reset itself when is sees pressure to both sides. Your "Repair" can to same thing from miss-alignment of the peaces, sealer/glue got in the spool area, and so on. (Your valve picture above isn't Fiero part. If original picture posted here then just to show fitting size.)
There seems to be some confusion as to what was and isn't damaged so I made a video. Apologize for the low light, storm front coming in. 84' Fiero SE combination valve adapter
[This message has been edited by mckaymotoworks (edited 03-12-2014).]
Yes. you can replace the fitting when Line nut strip the hole. Be careful you don't strip the body by over torquing the fitting. Before you ask, I have no torque value for that fitting.
Tighten new fitting then Use 2 wrenches to tighten line nut. second wrench to prevent over torque fitting/body threads.
Ok now we're getting somewhere. Maybe I wasn't clear, the only reason I asked about the thread pattern of the inside of the CV, indicated by pink arrow, was if I were unable to locate the stock fitting, maybe I could source one from Wilwood, Russell etc. that would work. But that's moot now as FS sent one.
I successfully got all the lines connected and functioning though there's still some air in the system after bleeding in sequence 6-7 times, 2 person method. I did have to take the master cylinder off to insure the fittings spun into the threads correctly on the combo valve, do not have the tools/supplies available to bench bleed, though I suspect the MC needs to be replaced, even if just for the reason it appears to be the original.
Brakes function enough to get the car sold, the new owner will need to replace the entire suspension and address the MC at that time, having it properly bench bled etc.
