1969 Corvette (C3) Master Cylinder And Brake Bleeding

[@tyronemorina4306]

On the rear there is a inside blender why didn't you do that one?

[@07HDFatboy]

I watched you put the lid on your master cylinder on both of your videos without pushing the rubber diaphragm gasket back to the correct position. You left it hanging down, it should have been pushed back up, so that it is not hanging down in the brake fluid.

[@darkleg7355]

If you had a second person pumping the brake pedal, would you still need to remove the master cylinder to bleed it?

[@carlosparra7516]

hi love your video. I have a 69 vett with all disk brake system. I dont have a booster. should I add one ?

[@ckstaff]

Kind of pricey, not to hard of a job, takes away originality of the car if it is original. I have the same, not a power brake system. I go back and forth on that question, should I or shouldn't I. So far my gut keeps telling me to leave it original but on the other hand how would anyone know the car didn't come with a booster? I am very hesitant on adding anything that border lines on modification even though the temptations to do so can be overwhelming.

[@jeffhaugh2781]

What about the second bleeder valve on the calipers? You bled the one on the front of the caliper. Mine has another bleeder valve on each caliper. They're GM calipers.

[@inell6]

When bleeding the REAR brake calipers, do you only need to do the outside bleeder valve or should you do both top valves? Thanks.

[@lairdandbarbwegner5438]

Was a very thorough explanation. Thanks

[@johnmilner7603]

For the older cars, do not buy the metric master cylinder bleeder kit. Napa sells them but if you buy a Delco MC from Napa, it should come with a bleeder kit and will tell you in the description online at the Napa website.

[@TheCorvetteBen]

You should add "1969 C3 Corvette" to the video title so more people can find the video.

[@TheWhatisright]

Ben, good point. I may do that. Hope all is well with you and family at your location. I will be in Dallas next month for a conference.

[@klartava]

just did a master cyl. on my 80 corvette....9/16th line wrench for tube removal, but nuts on the master, are not 9/16th they are 14 mm. just a thought, think chevy went to metric in mid 70's.

[@keng3230]

Did you ever change the height of the jacks / jack stands or are the rears always lower than the fronts?

[@ferdinandwurm4159]

I have replaced all four calipers master cylinder lines and bleed the brakes for 2 weeks now when I have a full pedal and hit the brakes the rear wheels will stop for one maybe two seconds then they will start to roll again what seems to be the problem please help

[@ckstaff]

I wanted to see you test the breaks when you completed it. I am having issues with the front right brake and continually having to bleed it over and over as I am concluding air is seeping in where the tube brake line connects to the rubber line that runs to the caliper. I have been using the hand pump bleeder but looks so much easier doing the gravity bleed yet for some reason not feeling the confidence of doing so. As I have bled all the brakes and this issue continues to repeat it seems to only affect air bubbles in that front right caliper and doesn't seem to have any effects to the other 3. I was thinking perhaps I need to bleed the master cylinder but beings I only have problems in the 1 I am thinking that is not the issue. The rear calipers have 3 bleeders on each, why did you only choose the top front bleeder?

[@jamesbickford4769]

Was it my imagination, camera angle? It didn’t look like when you RE-installed the master cylinder it wasn’t plumb/level. It sure looked like it slanted towards the driver side???

[@goodboyringo9716]

Do you know the size of the red fittings that were used in the master cylinder?

[@TheWhatisright]

No, but the fittings were with the kit that I got from the auto store. In fact, the kit had several sizes that I picked from for the correct size.

[@goodboyringo9716]

Thanks for the reply, I asked the size of the fitting cause I have heard people having problems with some kits. I was going to make up a brake line fitting and attach a hose to it. thanks

[@berts4877]

I know you probably got this all sorted out by now, but thought I'd comment an observation for others. The fittings to the master cylinder are 2 different sizes. You can kind of tell in the video that the rear is larger. I used the same kit as Corvette Hop so it was not an issue as it included both sizes I needed.

[@alexanderfields4172]

that is a flare nut wrench sir. beautiful car!

[@TheWhatisright]

Thank you.

[@jakefriesenjake]

Actually, it's a line wrench.

[@DanPattonFotoZ]

With this method of gravity bleeding you don't need the speed bleeders right? Just tube both regular bleeders and go.

[@TheWhatisright]

No you do not.

[@bobbyread]

Why the bench bleed on the master? I normally only do that with a new master or if one of the reservoirs has drained too far.

[@TheWhatisright]

Robert, Very good question, I did that because all the fluid ran out the front brakes (front Cylinder of master Cylinder) do to a leak. That forced me to bleed the Master Cylinder and brakes. The rear cylinder (of Master Cylinder) still had fluid in it.

[@mcinkyt]

Brake fluid is a very effective paint remover - in a BAD way

[@TheWhatisright]

You got the right LOL I have seem many people with bare hands in brake build. Just think what it could if entering the body. Always best to be careful when using brake fluid. Corvette Hop

[@koollee]

Hello and thanks for this video. .. Question is, would you advise tilting the vehicle lower in the front as u gravity bleed front brakes?

[@TheWhatisright]

No, the front is fine. Keep the rear on the C3 Corvette lower than the fronr. I have set both the front and the rear even before and had to redo the bleeding several times. It always works best to have the rear lower than the from on the C3 Corvette.

[@zakspop]

@@TheWhatisright That totally contradicts what this guy at CSSB Inc. says. kzbin.info/www/bejne/aYGrh4t8mMmAoZY

[@countyorga4744]

This is soooo helpful. Thank you.

[@dougankrum3328]

Ok, so I've got a 73 with manual brakes, no air in system, master cylinder is good, but pedal goes to floor...are the calipers causing the problem?. rapid pumping of pedal gets a little firm, but goes away instantly after releasing the pedal. No leaks anywhere, bought a new master, but problem remains. Master is very solid with brakes lines removed and red plastic plugs in the 2 ports where lines connect. All calipers/pads replaced a while back, but car has been parked for a long time, brakes worked OK last time I moved it...about 6 months...

[@TheWhatisright]

Did you bleed the brakes correctly? I found that on the C3 Corvette, I had to bleed the brakes with the rear in lower than the front end of the car. Starting with the rear passenger side brake them the rear drivers side. I have a video on how to do that by gravity bleeding the brakes. Are the brakes firm once they are bleed? If not, that may provide you a good clue that they are not being bleed correctly. Yes, it is possible to have bad calipers or even a bad master cylinder, but check that bleeding process first. Plus, it is the cheapest thing to do before replacing parts. I would be happy to take with you on the phone if you would like to call.

[@ldog0206]

I have the same problem did you find a solution?

[@TheWhatisright]

Andrew, see my comments. Also, check for runout alone with all I mentioned in my comments.

[@dougankrum3328]

I have not worked on the car right now. I replaced all 4 calipers (with new) a while back, I had to pressure bleed to get the air out, then pedal was very firm and only depressed about 3/4"...'vacuum' bleeder and 'gravity' method didn't work at all....parked the car, now the pedal goes to the floor, I replaced the master cylinder, expecting the old (original) unit to be rusty and bypassing fluid, but it looked fine. and found no improvement. the front calipers are a little rusted, the rear look OK...The parts store counter man said these brakes were troublesome. He had a customer with a 1971 corvette that had so much trouble with the brakes, the guy sold it to get rid of the problem.

[@divenb1629]

that normally means theirs a leak somewhere causing it to not hold pressure

[@CCROSS5882]

Why cant you bleed the master cylinder in the Car? Nice work

[@berts4877]

Thanks for the video. I have an 82 and noted there is a bleeder valve on each half of the caliper. Do I need to gravity bleed both? If so which first? I replaced my driver side rear caliper which was leaking in case that makes a difference. Thanks.

[@TheWhatisright]

If you have a bleed valve on the back half of the caliper and one on the front half then both bleed valves will need to be bleed.

[@berts4877]

Thanks. I found another one of your videos where I saw you opened both bleeders on the caliper at same time. It wasn't clear on this video as it only showed the outer bleeder being opened with a hose connected so I wasn't sure if it was all that was needed since it is furthest from where brake line connects. Maybe it was the fact your problem was with the front brakes? Anyway I should be good now. Thanks again.

[@TheWhatisright]

You are welcome. Please post it it all works out for you.

[@berts4877]

It worked well after I fixed my leak by replacing the brake line and brake hose on the driver side rear. Only difference is the nuts holding my master cylinder to the booster are actually metric - 15mm which is between 9/16 and 5/8. Only took about 10 presses of the screwdriver to get all the air out of the master cylinder. I have a nice solid brake pedal now.😊 Thanks again.

[@TheWhatisright]

@@berts4877 I am happy to hear it all worked out.

[@alexisrobinson2453]

I'm not going to be driving my C3 much just to car shows and museums. So it will be sitting for long periods of time. I've read that dot 5 is the best option for that scenario. What are your thoughts?

[@kalani1987]

Dont think that's necessary. Heard Dot 5 is for racing applications due to extreme high heat tolerances. I would stick with Dot 4

[@correyy]

Dot5 is the better choice.

[@jakefriesenjake]

@@correyy dot 5 has its negatives. I'm running dot 5. Its literally 5 times more money. It is paint safe though. It won't absorb water, but if water somehow gets into the system, the water will eventually pool in an area and maby cause more rust. Oh, and if you switch from dot 4 to dot 5, you gotta take everything apart and flush all of the old dot 4 out. Pain in the toucas. They are not compatible.