Sticking Brakes

[Dr_EluSivE]

I just got finished swapping out a clutch in my 73 MG, so it has been sitting a while, and while driving i noticed that the brakes seem to be dragging, So i parked it for the day and went back later, jacked up the car, and all the wheels spin freely. So i took it for another ride and felt the same thing. This time i took it home and jacked it up right after i drove it and ALL 4 wheels were dragging badly. For some reason the fluid isnt pushing back when you let off the brakes. The MC is fairly new, as are both rear cylnders. And the system was flushed and filled with silicone brake fluid several years ago and the fluid in the MC looks clean. Is there a Prop. valve somewhere that could be clogged? Or does this sound like a bad or sticky MC? Anyone had the happen before?

Dr.

 

[mikespain]

After a run jack it up and undo a bleed nipple,if this frees all wheels then suspect the master cylinder,if it just frees the one wheel suspect the flexible hoses,if it has no effect suspect sticking wheel cylinders or over adjusted brakes.It is unlikely that all flexible hoses fail together!

 

[Bugeye58]

You didn't mention the age of the three brake hoses. If they are original, I would replace them immediately. As the inside of the hose deteriorates, the lining collapses and acts as a check valve, preventing the proper return flow of the fluid. They may look OK from the outside, but be garbage inside.
A common problem.
Jeff

 

[DrEntropy]

/bcforum/images/%%GRAEMLIN_URL%%/iagree.gif

Earlybird Jeff, ya beat me to it. /bcforum/images/%%GRAEMLIN_URL%%/wink.gif

 

[Bugeye58]

Trying to get up the ambition to go to work, Doc. I may just blow it off and do fun stuff today.
Jeff

 

[DrEntropy]

My plan precisely!

 

[Bugeye58]

You've convinced me. Fun stuff it is! Looks like a Fiat day.
Jeff

 

[DrEntropy]

ROAD TRIP!!!

Slither it down my way! /bcforum/images/%%GRAEMLIN_URL%%/smirk.gif

 

[Bugeye58]

Hmm. Let me do the maths.
8 gallon fuel cell.
1300 Abarth, twin 40 mm Mikunis.
4.68 rear gear.
1250 miles, one way.

Don't think I'll make it, Doc. /bcforum/images/%%GRAEMLIN_URL%%/jester.gif
Jeff

 

[DrEntropy]

RATS!

Well... I'll just drink YOUR portion of th' beer, then. /bcforum/images/%%GRAEMLIN_URL%%/wink.gif

 

[Bugeye58]

RATS!

Well... I'll just drink YOUR portion of th' beer, then. /bcforum/images/%%GRAEMLIN_URL%%/wink.gif

Fair's fair. I'll drink <u>your</u> share of the stuff in <u>my</u> fridge then! /bcforum/images/%%GRAEMLIN_URL%%/grin.gif
Jeff

 

[DrEntropy]

*sigh*

I *KNOW* what YOU stock.

DOUBLE rats!!

 

[DrEntropy]

You shopuld get yerself a "White Whale" or somefin. We've a 5K foot runway less than five minutes away. /bcforum/images/%%GRAEMLIN_URL%%/jester.gif

 

[Bugeye58]

Heck, for 200 bucks I can hop a flight and be there in 2.5 hrs. That's into TPA.
Jeff

 

[DrEntropy]

That's *ten* minutes away. /bcforum/images/%%GRAEMLIN_URL%%/wink.gif

I'll be orbitin' th' arrivals terminal in a clapped out, red Spider with leprosy. You'll hafta jump in as I roll by... clutch is kinda 'funny' y'see. /bcforum/images/%%GRAEMLIN_URL%%/devilgrin.gif

 

[Bugeye58]

Check your mail, Kiddo.
Jeff

 

[DrEntropy]

did-O.

 

[bugimike]

Back to the thread...Jeff and Doc. are right on all counts and I would also consider that you mentioned silicone fluid. Use of that may have caused some deterioration of the rubber parts either in the MC or the rubber hoses!!!

 

[Dr_EluSivE]

I Probably should replace the hoses. I have never messed with them since i have owned the car. However i suspect it might be the master cylinder since all 4 decided to drag at once. I should just order and replace all 4 pieces. As for the silicone brake fluid, i was told it actually helps the rubber and makes it last longer, And it doesn't hold moisture like the dot3 stuff does, thats why i use it. After replacing the MC every year due to pitted bores, i switched and haven't had a problem till now. Thanks for the help

Dr.

 

[bugimike]

I have been told that there are different rubber compounds, some affected by silicone and some not and that the rubber used in the brake systems of LBCs is affected! I personally cannot swear to it either way, but have opted to err on the side of caution! Perhaps someone with more knowledge will add to this!! /bcforum/images/%%GRAEMLIN_URL%%/thumbsup.gif