Brake Fluid Leak on Master Cylinder any Cheap Fix..?

Looking for the cheapest n' easiest way to repair a brake fluid leak...

The red dash BRAKE light came on again a couple weeks after filling the brake system reservoir and it was 99 % empty this time, YIKES..! A quick look under the hood shows fluid on one of the two plastic cups on the master cylinder... Can this be fixed without replacing the master cylinder..? Local NAPA new $72.00+ tax

Time to inspect the rear brakes, the rear 1/2 of the brake fluid reservoir was dry, maybe a leaking cylinder there? The front brakes looked ok when replacing the shock absorbers...

At least once fixed the truck will be faster:) Any input is appreciated...

Check underneath for any visible leaks. Damaged hard lines or hoses. It's probably the rear cylinders rather than the master cylinder. Chances are they are leaking inside the drum. You may see fluid on the inside rear tyres. Budget for new brake cylinders and shoes as when the brake shoe material gets soaked in fluid they are no good anymore

Be thorough on your brakes. A fix is a fix and it all comes down to getting it 100% operational. The master cylinder could be bypassing, wheel cylinders could be shot, a bad seal in a caliper or a cracked hose or line. If you're doing one wheel side of the brakes, do both (they're going to be in the same condition) A BMC isn't hard to rebuild either as long as the bore isn't pitted or gouged. And I think you can use a BMC from a Ram 50 or Raider with a single reservoir... I don't like messing with brakes, probably my least favourite thing to work on.

new master cylinder on ebay is 39.95 - the starion one with a larger bore is 44.95. Not a hard job to change out the master cylinder if that is the leaking part.

Thanks guys, I learned several important things from your experienced input and it helps me budget & plan the work... Brakes are not fun work for me but now I have enough info to get the truck back in 100% safe order n' like newer condition... It never occurred to me to inspect or repair more than just the one leaking brake thing... Will post what we find & fix...

Brakes are one of those things where I like to just replace them before they fail. The one time I didn't, my Ram50, I had a line burst in a panic stop. Someone pulled out across both lanes of travel on my side of the road and stopped. I was right at the braking threshold when the pedal went to the floor and I had to swerve in front of an oncoming truck to get around them.
Underbody spray had hidden the true condition of the steel line as it ran between the gas tank and the frame.
I ended up replacing every hose, and every line with the CuNiFe stuff. I also did the wheel cylinders. The cal-van in line flaring tool is a great product for reasonable money if you end up replacing lines. I have made many flares with it and cannot say enough good things about it. Short of a couple hundred dollar hydraulic one, I think it's the best one available. https://www.amazon.com/Cal-Van-Tools...ne+flaring+kit
Replacing everything might not be in you budget or skill set, but at least scrutinize every inch of line and hose.

Well, seems I better plan on inspecting everything in the braking system; so far this got done:

My neighbor's son-in-law replaced the master cylinder in our local Kailua O'Reilly's parking lot just outside their front door last night... He did the work for $50.00 + my part $67.00 NAPA new MBC (military discount) O'Reilly's no longer sells a new part... I was impressed that it took him a little less than two hours (while I watched TV at home)... His name is Vernon, a local Hawaiian fellow who never seems to wear a shirt n' has flip flop cladded bare feet... He is often seen working on people's cars in local parking lots from his camper shell topped Chevy pickup truck...

I take back all the bad things I might have said about him; he is very good at mechanicals & wrench turning... If I had done this job my hands & fingers would be full of painful cramps and it would take me all day...

A stop for gas today revealed 17.5 MPG one Qt low oil and dry cooling system overflow tank, fixed all that but noticed the inner fender well paint got removed under the leaking BMC... So, that paint should be fixed too...

Vernon said he tightened the loose valve cover fasteners and tighten the loose accelerator cable mount... Throttle response is noticeably improved, feels good to drive now...

Well, we shall see in the near future if more needs to be done... Thanks to you all :)

People wave a finger at someone who isn't a 'qualified' mechanic and call them 'shade tree' mechanics, but it's funny how someone would let themselves be lured into a shop and have their wallets ambushed. I helped out a friend with their 74 Mazda 808 a little while back. Spent some time on setting the ignition tune - dialled in the dwell, felt my way through the ignition curve, reset the gaps. Took me about 45 mins to get it as close to perfect as the badly clapped out carby would let me. He takes it into a shop to get the ignition relay sorted out, and the monkeys meddled with my tune. Did it 'by the book' and nerfed it. Glad you have your brakes sorted out now. Not fun having a master cylinder fail on you (happened to me once in a friends car, almost ended with me using the ass of a semi as a brake...)