1990 Master cylinder replacement! ARGH

[Dustoff529]

My '90 C4 had a loss of break effectiveness that eventually (in 24 hours) was a failure of brakes. New MC in order. After I got the old fluid out with a syringe, I removed teh Warning switch, which created my first issue with twisting up the wiring ALOT!( it WAS directly wired into the switch) I resolved that issue by getting a waterproof connector and cutting the wire putting the connector on adn twisted wire issue resolved. Next probled was that teh front flare nut (which btw is METRIC! the rear is NOT) had galled into the aluminum MC housing.... HACK SAW! new flare fitting on SS tubing .... WOW What a PAIN to flare! There was years of gunk (I have not owned the car since new) in the reserviours, cleand that out and flushed ALL lines and yeehaw I'm back in business..... But a 2 hour job took 4+ irritating

WHen I have your wounded

 

[CharlesBrown]

Been there, done that...I feel your pain! Wait 'till you have to replace the vacuum booster. Step 1. remove the driver's seat, if you're over 4' tall that is.

 

[bill5674]

just wondering...did you double flare?

 

[Dustoff529]

YES!

just wondering...did you double flare?

YEs I did but it was a REAL pain!

CHarlie

 

[bill5674]

iam sure it was...i usually get stuck chasing lines and hose just by looking at my master cylinder..

 

[Dustoff529]

Done! Save $400!

OK master cylinder done, brakes bled, stops great... dealer said, for them to do it $503 PLUS brake fluid...... I bought a Wagner reman MC for $38 (on sale) parts to fix the galled fitting $13 (on sale) and some other misc. parts to improve that sensor wiring issue.... ( The Wagner reman MC is identical to the one I removed, numbering and configuration..... )

Now since I saved some money, I get to go buy TOOLS!!!!!!!!!!!!

When I have your wounded
Charlie

 

[G Winter]

Now since I saved some money, I get to go buy TOOLS!!!!!!!!!!!!

Charlie

Sounds like a plan.

Nice to hear everything went well. Now if I have to do mine I know where to go for pointers.

Glenn

 

[Dustoff529]

Pointers

Sounds like a plan.

Nice to hear everything went well. Now if I have to do mine I know where to go for pointers.

Glenn

For ME, this surprise was the 10 mm flare nut for teh front brakes. That is the one that was galled. I would CUT the wire going to the sensor to start with (unless it comes apart from teh sensor) you can get water resistant connectors from Northern tool.(that's where I got mine) I found that I did not ned to tools to reseat teh composite reservouir lots of lube then press them in that follow with a brass punch to assure that teh INSIDE lip of teh seal is in the right place...Clean teh crap out of the resevouirs, new clean fluid, bleed your brakes and off you go!
Charlie

 

[Dustoff529]

Advice

When you replace the Master Cylinder also replace the "Switch Assembly- Warning" My pedal went to the floor yesterday, (yahoooo exciting) open hood and find 0 fluid in FRONT reservoir, refill, step on pedal and fluid is squirting our the top of that switch like a little kid peeing of a porch! Check on line and $18.00 called dealer, in stock for $17.52. < 3 min to change out rebleed front brakes and I'm rockin' again....

When I have your Wounded
Charlie

 

[Dustoff529]

Continuing SAGA! So this new switch has a very smalll hole between the electrodes that sprays brake fluild like the aforementioned kid! The dealer says only 1 PN, used '84 thru '95.... THe one that WAS inplace didnt have the small hole but the core of one of the electrodes blew out. (the new switch appears to have solid electrodes) SO I'm back to my plug and lacking a warning switch... Dealer suggested running VIN to check for TSB??? Suggestions???

When I have your wounded
Charlie

 

[Dustoff529]

Alas.. My saga continues

Continuing SAGA! So this new switch has a very small hole between the electrodes that sprays brake fluild like the aforementioned kid! The dealer says only 1 PN, used '84 thru '95.... THe one that WAS in place didnt have the small hole but the core of one of the electrodes blew out. (the new switch appears to have solid electrodes) SO I'm back to my plug and lacking a warning switch... Dealer suggested running VIN to check for TSB??? Suggestions???

When I have your wounded
Charlie

SO OK ya'll ideas?

Charlie

 

[milehigreg]

Try www.corvettemechanic.com. c4c5specialist may be able to help.

 

[Dustoff529]

Thanks I'll try them
CHarlie