how to plug a brake line during caliper change?

What's the best way to keep all of the brake fluid from pouring out? I need to have the caliper removed for a while for cleanup and rebuild.

I usually use that as a chance to change the brake fluid and just let it run into a pan.

Otherwise, I'd probably use a nitrile glove and a rubber band.

Put a piece of broom handle between the seat and the brake pedal, then move the seat forward about an inch. This pushes the MC pistons past the comp ports, and prevents the MC from draining.

Work fast?

The only ways that work well are clamping the hose, or depressing the brake pedal.

Get a short length of line, screw it on to theline removed from the caliper. Roll it and then pinch shut with vice grips.
But I agree, change the fluid.

Hard line, a vacuum cap will work.

Banjo fitting, slip an appropriately sized chunk of vacuum hose through the banjo hole to close it off.

It'll just drool a bit. If you let it drool, you minimize the amount of air that gets in, speeding up your bleeding time. If you install the caliper with the bleeder cracked open, by the time you've got the line attached you'll basically have bled the caliper too. Makes life really easy.

Foam rubber ear plug. It will swell up and block the line until you can reassemble everything.

If I am going to have it open for a long time, I put some plastic wrap on top of the reservoir and screw the cap back on. This keeps the air out and the fluid in.

Let it drip.. you need to change the fluid anyways, right? And when you put it back together, leave the bleeder open and it will bleed itself in seconds.

You could use these:

http://www.amazon.com/Tool-Aid-19700-8-Piece-Adjustable/dp/B00FQHKV1K

Or just let it drip.

The ear plug is a good idea. It's easy to slow the dripping but hard to stop. Even a twisted-up paper towel jammed through the banjo fitting will slow it down.

Edit: For a straightforward caliper change, +1 for "work fast."

They sell a tool for this near the "Help!" section of the autoparts store. It's just a rubber plug. On one end you can cap a line, on the other end, you can plug up a banjo fitting.

http://www.autozone.com/brakes-and-traction-control/brake-hose-plug/dorman-brake-hose-plug/441046_52744_0/?checkfit=true

DON'T LET DRIPPING BRAKE FLUID GET ON THE PAINT!

I've never seen instant damage from brake fluid on paint, only when it's allowed to sit. Has anyone else, or is this one of those things we learn from our fathers and never question?

Armitage wrote: They sell a tool for this near the "Help!" section of the autoparts store. It's just a rubber plug. On one end you can cap a line, on the other end, you can plug up a banjo fitting. http://www.autozone.com/brakes-and-traction-control/brake-hose-plug/dorman-brake-hose-plug/441046_52744_0/?checkfit=true

Thanks! I'd been considering the ear plug option but didn't know those existed. When purging air from your ABS pump requires a trip the the dealer, or buying some $$$ equipment to do it yourself, you don't want to just "let it drip."

bigdaddylee82 wrote: Thanks! I'd been considering the ear plug option but didn't know those existed. When purging air from your ABS pump requires a trip the the dealer, or buying some $$$ equipment to do it yourself, you don't want to just "let it drip."

I'm learning here. I always thought that if you just let it drip, eventually you would empty the reservoir (in the extreme take a caliper off and don't replace it until next weekend) and that would be bad for getting air in the system, doubly so for an ABS equipped car. "Work fast" has been the MO in the past, but was trying to find best practice and learn from others here in the event that I pull a caliper off and then have an uh-oh moment.

Keith Tanner wrote: I've never seen instant damage from brake fluid on paint, only when it's allowed to sit. Has anyone else, or is this one of those things we learn from our fathers and never question?

It doesn't cause instant damage but I don't know how long it takes to eat at the paint. I had some brake fluid on my firewall for a couple of hours before it was rinsed off so I guess I'll find out soon enough...

glueguy wrote:

bigdaddylee82 wrote: Thanks! I'd been considering the ear plug option but didn't know those existed. When purging air from your ABS pump requires a trip the the dealer, or buying some $$$ equipment to do it yourself, you don't want to just "let it drip."

I'm learning here. I always thought that if you just let it drip, eventually you would empty the reservoir (in the extreme take a caliper off and don't replace it until next weekend) and that would be bad for getting air in the system, doubly so for an ABS equipped car. "Work fast" has been the MO in the past, but was trying to find best practice and learn from others here in the event that I pull a caliper off and then have an uh-oh moment.

You will empty the reservoir eventually but it'll take a fair bit of time. You don't need to work super-fast, just don't take a long lunch break

If you can't put the new caliper on for some reason, then I'd look at either crimping the line or putting the old caliper back on.

I don't get why bleeding the brakes is an issue. These are freaking brakes! You need them to work 150% of the time! Just do it right!!!!

Are there any downsides to clamping the flex line shut? I know that sometimes old flex lines will swell internally and stop the flow of fluid. Would clamping the flex line accelerate the failure at all?

stanger_missle wrote: Are there any downsides to clamping the flex line shut? I know that sometimes old flex lines will swell internally and stop the flow of fluid. Would clamping the flex line accelerate the failure at all?

Hohohooo yes, don't do that.

stanger_missle wrote: Are there any downsides to clamping the flex line shut? I know that sometimes old flex lines will swell internally and stop the flow of fluid. Would clamping the flex line accelerate the failure at all?

Voice of experience here. Many years ago I paid a "mechanic" to replace my front calipers (I hadn't figured stuff like that out yet) and he crimped the flex lines.

Fluid gets trapped past the crimp and builds pressure on the piston causing dragging/burned up brakes. We had words and he had to replace a lot more parts.

if you leave the cap on the master cylinder, you could probably let it sit over night and still have a half full reservoir.. if you take the cap off, you might have a couple of hours..

In reply to Trackmouse:

Sure bleeding them typically isn't that big of an issue, until like I stated above, you've let the reservoir/master go empty, and now there's an air pocket in the ABS circuit, which on a Chrysler/Jeep product is more often than not going to require a DRB (dealer only) scan tool to bleed the ABS pump.

So say you're doing more than just calipers, maybe swapping an axle, you want to find a way to keep as much fluid in the system as possible.