Brake Fluid Leak under Master Cylinder

[JessEm]

I have leaking brake fluid. It's under the MC. Appears to be right at the connection where the MC bolts on. There appears to be a hole it's coming from... Has anyone seen this before? Comments suggestions questions welcome. Any ideas at all what my next play should be. Thank you.

Underside of Master Cylinder. Leak is just before the double metal flange along the bottom.




The "hole". Basically, right on the seam when MC bolts on.




Another view.




Looking directly up.




Thanks for any help.

[Rickf1985]

Master cylinder seals are leaking, time for a new one.

[jeno]

ya that seal is SHOT.

[JessEm]

THANKS Fellas! ... So... Is this just a matter of taking out the two bolts and replacing the gasket? Or is there more to this than meets the eye? I'm guessing I should expect brake fluid to pour out once it's undone?

[jeno]

no gasket just the two bolts and the two lines

[JessEm]

2 lines??!! Now I'm confused. What can I expect to find after the bolts are out and I've opened this up? Is there 2 lines running through that tube?

[Froggy1936]

Jess the cure for the leak is to replace the master clyinder, The two lines are the ones going to the wheels The seal that is leaking is part of the master cly . Yes you will have to bleed the system ,Recommend bleeding ea wheel till clean fluid comes out , Do not let the master cly go empty ! Frank

[GONMAD]

This is NOT for unexperienced. You have a Hydroboost brake system I think & it usually takes a lot of patience & should be careful. Be sure to pre bleed the new master cylinder before you install it on your rig. If your careful you might NOT have to bleed the whole system but don't be afraid to tackle this.
  "If you can't stop it DON'T start it" That's how I build vehicles. Brakes FIRST! Then on to the fun. Just my two cents... C YA! GONMAD 

[DaveVA78Chieftain]

You have a 1976 M400 chassis with Hydroboost.  Most of the information you need will be located here: M400 1976 and Later

Dave

[Rickf1985]

The seal that is leaking is the piston for the front brakes. This is not something that is normally replaced. You may or may not be able to find a rebuild kit but I would STRONGLY advise against it. This is serious enough that it is illegal for me to rebuild one since I am a certified mechanic. I guess that means I should know better. I do, I buy new ones.

[JessEm]

Thanks everyone for all the info. Never would've guessed a leak along the seam required a whole new MC. Thanks to Dave's post I ended up tracking down this on ebay: http://www.ebay.com/itm/361055151632

Does anyone know how much shop time I should expect for this if I take it in?

[Rickf1985]

I can't give you an estimate on shop time because I am not familiar with your vehicle but I can tell you that I would refuse to put any brake parts on that a customer brought in to my shop. I was not going to be responsible for someone elses parts going bad, you don't know where they came from. If they do it at all I doubt they will warranty the job. It is probably best to let them get the parts and that way if there is a problem you are covered.

[JessEm]

Thanks Rick.

Last time they were real honest about it. Said they couldn't even buy the parts for what I paid, and they were the same parts. Saved me $350ish.

[Rickf1985]

But were they brake parts? Hey, if they are willing to do it then go for it.