Brakes not working after caliper replacement

[Elvolvito]

So I just now replaced the rear left brake caliper on my ?88 244 & now the brake pedal just goes to the floor every time I step on it. I did pump the brakes a lot before putting force into them, but I guess it didn?t work? My brake line is on tight & isn?t leaking whatsoever. I also forgot to mention that I opened my brake fluid reservoir before replacing it so there would be no intense air pressure in the lines. Do you think air got into my lines? How do I go about solving this? Do I need to bleed my brakes? & if so, how do I go about that?

 

[Lando]

Yes, you’ll need to bleed your brakes. Anytime you break loose any line you will need to bleed the brakes. You should be able to just crack open the bleeder and it will gravity bleed. It may take 10-20 minutes, and make sure you keep the reservoir from running dry or you’ll have to start over. Also make sure the pedal is all the way up before you start. Try not to floor the brake pedal when you pump up the brakes.

Ps, you might want to bleed some fluid through on all four corners if you don’t know when it was done last.

 

[Elvolvito]

Yes, you?ll need to bleed your brakes. Anytime you break loose any line you will need to bleed the brakes. You should be able to just crack open the bleeder and it will gravity bleed. It may take 10-20 minutes, and make sure you keep the reservoir from running dry or you?ll have to start over. Also make sure the pedal is all the way up before you start. Try not to floor the brake pedal when you pump up the brakes.

Ps, you might want to bleed some fluid through on all four corners if you don?t know when it was done last.

Ah, got it. I?ll do this whole process tomorrow. Also, the bleeder is on the caliper correct? (Sorry if this is a dumb question, I?m new to brakes & how they function)

 

[tintintin]

Also, the bleeder is on the caliper correct?

Correct.

Pay attention to Lando's advice to not depress the brake pedal further than it normally travels. Doing so can prematurely ruin the master cylinder by forcing the rubber piston seals into the rough corroded area of the cylinders, ruining their sealing ability.

 

[MasterBlaster]

I?m new to brakes & how they function

The brake fluid reservoir supplies fluid to the master cylinder.

When you press the pedal, the master cylinder pumps the fluid through the lines to the caliper.

The pistons in the caliper are forced partly out of their holes, and against the pads, by the pressure of the fluid pumped in behind them.

Here's a VERY simplified picture from the web...

The caliper you installed is empty.
There's only a little bit of air behind the pistons.
Air compresses easily, fluid doesn't.
You need to replace all the air with brake fluid.

-

Keep the reservoir full of brake fluid at all times!
Attach a hose to the bleeder (clear plastic is best, so you can see what's happening), and stick the other end in something to catch the mess. No hose? Hope you have lots of towels!
Open the bleeder on the caliper.
A mix of fluid and air bubbles will come out for a while.
You need to wait until there are no more bubbles.
That's "gravity" bleeding.

Some people will have vacuum bleeders that attach to the caliper and suck the fluid and bubbles out.

Some will have a pressure bleeder that attaches to the reservoir and pushes fluid through.

Some have a friend who can sit in the car and press the brake pedal for them. Close bleeder, friend holds pressure on pedal, open bleeder, "whoosh" fluid comes out, close bleeder, foot off pedal. Repeat until no more bubbles.

 

[Elvolvito]

Yes, you?ll need to bleed your brakes. Anytime you break loose any line you will need to bleed the brakes. You should be able to just crack open the bleeder and it will gravity bleed. It may take 10-20 minutes, and make sure you keep the reservoir from running dry or you?ll have to start over. Also make sure the pedal is all the way up before you start. Try not to floor the brake pedal when you pump up the brakes.

Ps, you might want to bleed some fluid through on all four corners if you don?t know when it was done last.

Quick question, when it comes to gravity bleeding my rear left caliper, do I keep the fluid reservoir open during the whole procedure & consistently be putting brake fluid into it as the bleeder rushes out the old liquid? At what moment do I need to pump the brakes? When do I stop pumping them?

 

[Elvolvito]

The brake fluid reservoir supplies fluid to the master cylinder.

When you press the pedal, the master cylinder pumps the fluid through the lines to the caliper.

The pistons in the caliper are forced partly out of their holes, and against the pads, by the pressure of the fluid pumped in behind them.

Here's a VERY simplified picture from the web...

The caliper you installed is empty.
There's only a little bit of air behind the pistons.
Air compresses easily, fluid doesn't.
You need to replace all the air with brake fluid.

-

Keep the reservoir full of brake fluid at all times!
Attach a hose to the bleeder (clear plastic is best, so you can see what's happening), and stick the other end in something to catch the mess. No hose? Hope you have lots of towels!
Open the bleeder on the caliper.
A mix of fluid and air bubbles will come out for a while.
You need to wait until there are no more bubbles.
That's "gravity" bleeding.

Some people will have vacuum bleeders that attach to the caliper and suck the fluid and bubbles out.

Some will have a pressure bleeder that attaches to the reservoir and pushes fluid through.

Some have a friend who can sit in the car and press the brake pedal for them. Close bleeder, friend holds pressure on pedal, open bleeder, "whoosh" fluid comes out, close bleeder, foot off pedal. Repeat until no more bubbles.

Aw man, I?m so lost. I just added some brake fluid to my reservoir but the back portion of it is still empty? I?m not sure what to do?

https://imgur.com/gallery/AbBNSUg

 

[Lankku]

Reservoir has a divider and you just have to fill more.

 

[Elvolvito]

I feel so defeated. The nipple on the rear left caliper won’t release any fluid, however, when I disconnect the brake line, fluid comes out fine. There was even fluid inside the caliper. I don’t know what I’m doing wrong? I’m doing the basic gravity bleed & am I supposed to create some type of suction on the nipple? Do I have to bleed out all 4 calipers even though I only replaced one?

 

[dl242gt]

I've never had much success gravity bleeding on a 240. I've had that work great on British sports cars on the brakes and the clutch system. But for the 240 series after having a few too many challenging brake bleeding adventures. I bought a Motive pressure bleeder and the pain and hassle of brake bleeding went away.

 

[Redwood Chair]

I've never had much success gravity bleeding on a 240. I've had that work great on British sports cars on the brakes and the clutch system. But for the 240 series after having a few too many challenging brake bleeding adventures. I bought a Motive pressure bleeder and the pain and hassle of brake bleeding went away.

+ 1,000,000 Best ~ $60 I ever spent.

I feel so defeated. The nipple on the rear left caliper won’t release any fluid, however, when I disconnect the brake line, fluid comes out fine. There was even fluid inside the caliper. I don’t know what I’m doing wrong? I’m doing the basic gravity bleed & am I supposed to create some type of suction on the nipple? Do I have to bleed out all 4 calipers even though I only replaced one?

Carefully twist / poke out the bleed screw hole with a small drill bit.

Yes you will need to bleed the entire system at least twice after performing any work on the system to be sure you have a good pedal.

 

[tintintin]

I?m new to brakes & how they function

Don't let the brake fluid get all over. It eats the paint and other finishes, including any that make your rims pretty.

 

[MasterBlaster]

I feel so defeated. The nipple on the rear left caliper won?t release any fluid, however, when I disconnect the brake line, fluid comes out fine.

Quick side question... is the replacement caliper new or used?

As for no fluid flow, sometimes (with gravity bleeding) it takes a while for the caliper to fill up enough to "overflow" out the bleed nipple. Did you open it enough? Usually 1/2 to 2 turns should do it.

If the caliper is used, there could be some rust plugging up the tiny hole the bleed screw seats in. As suggested, take the bleed screw out completely and poke something tiny in the hole to dislodge any crud. If the caliper is new or rebuilt, maybe there's some kind of "assembly lube" plugging the hole that needs a bit of help (beyond gravity) to get it out. A quick stab on the brake pedal (bleeder open) will often help get the fluid moving.

 

[Elvolvito]

I've never had much success gravity bleeding on a 240. I've had that work great on British sports cars on the brakes and the clutch system. But for the 240 series after having a few too many challenging brake bleeding adventures. I bought a Motive pressure bleeder and the pain and hassle of brake bleeding went away.

How does the procedure for using a pressure bleeder work? Just hook it up, open the valves, & pump away?

 

[Elvolvito]

I think I’m just going to do the 2 person brake pump method later today & I’ll update this thread afterwards.

 

[Elvolvito]

Quick side question... is the replacement caliper new or used?

As for no fluid flow, sometimes (with gravity bleeding) it takes a while for the caliper to fill up enough to "overflow" out the bleed nipple. Did you open it enough? Usually 1/2 to 2 turns should do it.

If the caliper is used, there could be some rust plugging up the tiny hole the bleed screw seats in. As suggested, take the bleed screw out completely and poke something tiny in the hole to dislodge any crud. If the caliper is new or rebuilt, maybe there's some kind of "assembly lube" plugging the hole that needs a bit of help (beyond gravity) to get it out. A quick stab on the brake pedal (bleeder open) will often help get the fluid moving.

The caliper is new.

 

[dl242gt]

How does the procedure for using a pressure bleeder work? Just hook it up, open the valves, & pump away?

A pressure bleeder is a small pressure tank like a pressure sprayer you use to spray weed killer. You fill the tank with brake fluid and connect to the brake reservoir. Pressurize the tank upto about 15psi and then you go around and let the pressure push the bubbles and bad fluid out. With a pressure bleeder you can save time and hassle. In fact some people have made their own pressure bleeders with garden sprayers.

 

[Lando]

Quick question, when it comes to gravity bleeding my rear left caliper, do I keep the fluid reservoir open during the whole procedure & consistently be putting brake fluid into it as the bleeder rushes out the old liquid? At what moment do I need to pump the brakes? When do I stop pumping them?

Yes remove the cap and keep it topped off. I?ve actually usually invert a can of brake fluid and leave it there, it will keep the reservoir topped off but not overflow. Don?t pump the pedal up until your done. If you bleed with a friend pressing the pedal, you have to make sure you close the bleeder before you allow the pedal to return to the top of its stroke.

 

[Elvolvito]

Yes remove the cap and keep it topped off. I?ve actually usually invert a can of brake fluid and leave it there, it will keep the reservoir topped off but not overflow. Don?t pump the pedal up until your done. If you bleed with a friend pressing the pedal, you have to make sure you close the bleeder before you allow the pedal to return to the top of its stroke.

Thank you, those are the small details I was looking to figure out. I wasn?t sure when to have my friend release the brake pedal. Also, when my friend goes to press the brakes down a bit, should he pump it a few times first, or just press it halfway down?

 

[arsenix]

Do you have a friend who knows what they are doing who could come over and help you with this? No offense but please don't kill yourself Youtube brake bleeding!