Help! Bleeding clutch, now worse!

[Beachdrifter]

Hi all,

So today I decided to bleed my clutch. Really I had no problems shifting in all gears except going in reverse when car was hot. At that point it had a slight grind in reverse.

I figured I'd check the clutch line for air. Well, my pedal was pretty stiff prior to bleeding. When I first bled, I noticed a plethora of bubbles in the fluid, and after several iterations of this, the pedal is now considerably softer and it seems bubbles just won't go away or subside. I've filled the reservoir at least 3 times and can't seem to get the air out!

I've made it worse now, when I start the car the gears are hard to shift and all grind!

Please help, thanks so much for any insight. Also I have to add that prior to this I had no leaks, so I can't imagine air being introduced into the system just from today.

Randy

[Iznodmad]

How long since fluid was last changed and what did it look like? How long since master cylinder and slave cylinder have been changed? Perhaps you just disrupted the "delicate balance of crud".

[Beachdrifter]

How long since fluid was last changed and what did it look like? How long since master cylinder and slave cylinder have been changed? Perhaps you just disrupted the "delicate balance of crud".

The fluid came out not extremely dark, but noticeably brownish. I did not see any solid particles in it. The slave and master was Changed when I had the clutch changed about 2 yrs ago.

This is a classic case of trying to fix something that really wasn't that bad and I just had to mess with it, and now it's worse.

Thanks

[DMCMW Dave]

The fluid came out not extremely dark, but noticeably brownish. I did not see any solid particles in it. The slave and master was Changed when I had the clutch changed about 2 yrs ago.

This is a classic case of trying to fix something that really wasn't that bad and I just had to mess with it, and now it's worse.

Thanks


Pretty common. With brake and clutch hydraulics, if you don't know the history and the fluid is darker than Coca-Cola, flushing it will almost always tear up the seals. Now you should replace/rebuild the master and slave. If you are still running the original black line from the front to the back, change that too.

[DMC-81]

Hi Randy,

Does it have the plastic line or the SS one? That may help diagnose the original grinding in reverse when the car is hot.

When I did mine, I had to make sure I only opened the bleed screw after my assistant depressed the clutch, and then closed it tightly before they released the pedal. I didn't get it tight enough a couple times and had to start over.

Also, (this is just a shot in the dark), but does your slave cylinder have the plastic washer where the hard line fitting goes into the slave? I read a post from Dave S that described that plastic washer sometimes allowing air to get in but no fluid to escape. I think he recommended a copper crush washer instead.

[Beachdrifter]

Pretty common. With brake and clutch hydraulics, if you don't know the history and the fluid is darker than Coca-Cola, flushing it will almost always tear up the seals. Now you should replace/rebuild the master and slave. If you are still running the original black line from the front to the back, change that too.

Ouch, I hope I don't have to change out the master and slave, worst case I will though. Thanks.

[Beachdrifter]

Hi Randy,

Does it have the plastic line or the SS one? That may help diagnose the original grinding in reverse when the car is hot.

When I did mine, I had to make sure I only opened the bleed screw after my assistant depressed the clutch, and then closed it tightly before they released the pedal. I didn't get it tight enough a couple times and had to start over.

Also, (this is just a shot in the dark), but does your slave cylinder have the plastic washer where the hard line fitting goes into the slave? I read a post from Dave S that described that plastic washer sometimes allowing air to get in but no fluid to escape. I think he recommended a copper crush washer instead.

Thanks Dana, when I changed out the clutch a few yrs ago I had a SS line installed and also new slave and master.

Thanks for your insight on the bleed process. I will make sure to tighten well. I also was not aware of the washer issue. I honestly don't know what washer is installed, but it's a good lead for possible air entry.

Other than that washer, . What are other sources of air getting sucked in?

[content22207_2]

Really old VW Beetles are bad for this in their brake lines. Rather than pushing from the master cylinder, pulling fluid at the brakes with a hand vacuum pump works better. Many vacuum pump kits come with a little jar for that purpose. Just keep refilling the reservoir and emptying the vacuum jar until all the bubbles are gone.

Bill Robertson
#5939

[DMCMW Dave]

Really old VW Beetles are bad for this in their brake lines. Rather than pushing from the master cylinder, pulling fluid at the brakes with a hand vacuum pump works better. Many vacuum pump kits come with a little jar for that purpose. Just keep refilling the reservoir and emptying the vacuum jar until all the bubbles are gone.

Bill Robertson
#5939

I don't recall that he was working on an old beetle. Or brakes.

I find that using a suction bleed pulls air around the bleeder and you can't tell when you are done. To each his own. Never had any problem pressure bleeding a DeLorean clutch unless something is wrong with the master cylinder. Typically the slave just leaks fluid out and not air in.

[Beachdrifter]

Really old VW Beetles are bad for this in their brake lines. Rather than pushing from the master cylinder, pulling fluid at the brakes with a hand vacuum pump works better. Many vacuum pump kits come with a little jar for that purpose. Just keep refilling the reservoir and emptying the vacuum jar until all the bubbles are gone.

Bill Robertson
#5939

Bill, thanks for sharing this method. Perhaps vacuum will have better results. I went ahead and ordered one from eBay for 20 bucks, can't hurt to try. It does seem like pumping the pedal just makes everything go haywire in there.

[Beachdrifter]

I don't recall that he was working on an old beetle. Or brakes.

I find that using a suction bleed pulls air around the bleeder and you can't tell when you are done. To each his own. Never had any problem pressure bleeding a DeLorean clutch unless something is wrong with the master cylinder. Typically the slave just leaks fluid out and not air in.

I sure hope my cylinders aren't the culprit. I mean everything just seemed working pretty good before I did this today. I'm open to anything at this point.

[kings1527]

I don't recall that he was working on an old beetle. Or brakes.

I find that using a suction bleed pulls air around the bleeder and you can't tell when you are done. To each his own. Never had any problem pressure bleeding a DeLorean clutch unless something is wrong with the master cylinder. Typically the slave just leaks fluid out and not air in.

Dave,

What fitting/adapter do you like to use on the clutch fluid reservoir when pressure bleeding?

[content22207_2]

I don't recall that he was working on an old beetle. Or brakes.

But he is having a hard time getting rid of air, which is the same thing that happens on vintage Beetle brakes (which also only have one piston in their master cylinder, just like a clutch master...).

I was merely suggesting something I've seen work with my own eyes from the back end of another car.

Bill Robertson
#5939

[content22207_2]

Bleeder jar that came with my vacuum pump (Mighty Vac):

44611

Not very popular on this forum, but it does work....

Bill Robertson
#5939

[Bitsyncmaster]

i commonly get little air bubbles that never go away bleeding hydraulics. I guess it sucks a little air in around the bleeder threads when releasing the pedal. A pressure bleeder would not do that.

When I first bled my clutch, it still worked but a week later the slave was leaking fluid. I don't think the clutch fluid was ever bled because the fluid was so black. I now have Hervey's remote bleeder line.

[Citizen]

I sure hope my cylinders aren't the culprit. I mean everything just seemed working pretty good before I did this today. I'm open to anything at this point.

I had a similar original situation you described, where it started out as a nuisance, with reverse being hard to get into, then slight grinding, then forward gears got harder and harder, until I eventually had to do something about it. So don't feel bad about being proactive on maintenance...eventually you would have had to address this, better to do it now.

In my case, I was losing fluid, although I never saw any on the garage floor. At the suggestion of some great helpers on this forum (one of the Daves), I traced signs of master cylinder fluid loss to two places,
1) on the carpet behind the clutch pedal, there were small black stains that I hadn't noticed until looking for it, and
2) on the top side of the gas tank cover panel on the bottom of the car (had to remove to see). Fluid was collecting on the top of the gas tank cover panel, and slowly eating it away. Damage had already been done when I got to it, so I had to remove as much corrosion as I could, and then POR-15 before replacing.

I bet you'll find one or both of the situations above.

I ended up replacing the MC and then bleeding until fluid looked clean. Didn't try to replace the SC because I found no evidence of fluid loss back there like I did in the front. That and being extremely hard to get to also figured in to deciding to hold off on the slave for now, but I know I will eventually have to get to it.

Thomas

...

[DMC-81]

I don't recall that he was working on an old beetle. Or brakes.

I find that using a suction bleed pulls air around the bleeder and you can't tell when you are done. To each his own. Never had any problem pressure bleeding a DeLorean clutch unless something is wrong with the master cylinder. Typically the slave just leaks fluid out and not air in.

When I replaced my plastic and hard line, and slave, I tried pressure bleeding to get the fluid though the line. But I never got fluid up to the slave. I tried a vacuum pump, and it worked great at pulling the fluid through the line.

However, the vacuum pump was not very effective at bleeding the air out. As Dave mentioned, air was getting sucked in at the bleeder valve.

So I think a vacuum pump has it's value on the Delorean clutch, but not bleeding air.

[Soundkillr]

When I replaced my plastic and hard line, and slave, I tried pressure bleeding to get the fluid though the line. But I never got fluid up to the slave. I tried a vacuum pump, and it worked great at pulling the fluid through the line.

However, the vacuum pump was not very effective at bleeding the air out. As Dave mentioned, air was getting sucked in at the bleeder valve.

So I think a vacuum pump has it's value on the Delorean clutch, but not bleeding air.

Agreed. A vacuum pump does not work well to finish bleeding. I quit using mine years ago because I got the same result. Pulled air right past the bleader threads....

[content22207_2]

I normally use a coke bottle:

44613 44614 44615

On a line full of air (such as replaced brake line) I've found pulling fluid through works better. Kind of like priming a pump. I may finish off with the coke bottle, but to fill the lines with fluid I start with a vacuum pump.

Bill Robertson
#5939

[Beachdrifter]

Thanks all, very good points.

I'm starting to think that my ineffective bleeding may be due to air being sucked in through the bleeder threads. If I take the bugger out and put some Teflon tape will this help?

I'm open to all the methods described to get pressure for bleeding ( ex. pedal pumping, vacuum, power bleeder)

As I mentioned, Im pretty confident I never had ANY leaks, because my reservoir was constantly at same levels, so even though I never saw fluid on garage floor, I doubt there was any fluid accumulated elsewhere.

Thanks,

[Citizen]

As I mentioned, Im pretty confident I never had ANY leaks.

So was I. But I'd check the things I referenced anyway. You may be surprised.



I doubt there was any fluid accumulated elsewhere.


So was I. It doesn't seem to accumulate, it just eats into your frame epoxy, and painted parts, then goes to work on the metal underneath.

...

[Beachdrifter]

I'll cover all the bases.

I'm also going to take advantage of my Motive power bleeder and ordered the adapter. I heard this one will work for our resevoir cap if anyone else is interested. VW Adapter part 1104.

http://m.ebay.com/itm/Motive-Products-27mm-threaded-adapter-for-Power-Bleeder-fits-air-cooled-VW-/391335430691?nav=SEARCH

[content22207_2]

If you've already got fluid in the lines, just bleed them with a coke bottle. I've been doing it that way for a quarter century no problem.

I only pull fluid through when there's too much air in the lines. My experience has been with too much air the pedal will fall to the floor and not even come back up.

Bill Robertson
#5939

[Bitsyncmaster]

A vacuum bleeder will work fine, it's just hard to tell when you have the air out of the lines. It won't hurt pulling air around the bleeder threads.

[content22207_2]

Speaking of vacuum pumps: I just accidentally overfilled the brake assist reservoir on my school bus. This is what two squeezes of the vacuum pump pulled out:

44620

One of these days I am going to make a bigger fluid jar from a peanut butter jar -- a vacuum pump pulls a *LOT* of fluid.

Bill Robertson
#5939

[David T]

If you have to use a vacuum to bleed the brakes grease up the threads of the bleeder screw to help prevent leaking air. Always a better method to use pressure if possible and is the better way to do it for the Delorean clutch. You do not need a helper if you use a "One Man Bleeder" which is nothing more than a check valve in the hose attached to the bleeder to prevent air from getting in. If you find you can't seem to get rid of all of the air you probably need to rebuild the cylinders ESPECIALLY if you are using the vacuum method, it can draw air in through the leaking seals, not just the threads of the bleeder screw! If your clutch fluid is dark you probably need to flush your brake fluid too.

[content22207_2]

a "One Man Bleeder" which is nothing more than a check valve in the hose attached to the bleeder to prevent air from getting in.

Actually a one man bleeder is nothing more than a hose immersed in brake fluid. Air bubbles pushed through rise to the surface. When the pedal is released fluid from the bottom of the bottle gets pulled back in:

44630 44631

Bill Robertson
#5939

[Beachdrifter]

Thanks all for your replies.

Live and learn. So I finally got to it today. I received my cap in the mail to hook up my power bleeder to the clutch resevoir. It wasn't a perfect fit, but I was able to still make it work.

What I found out that when bleeding the clutch the best method is in fact the power bleeder. By using this method I was able to most certainly get a steady stream of fluid and no bubbles. Using the pedal to do this instead resulted in too much line disturbance that resulted in a froth of bubbles that seemed impossible to get out.

So now my clutch pedal is nice and firm, shifting is smooth through all gears. We're back in business!

Invest in a power bleeder to save yourself headaches.

Or try all the methods available to you to see which one will get you the results you need. If you still have problems, I can only assume you have a mechanical issue with the slave or master.

Have fun!
Randy

[content22207_2]

Like I said, I've run into the exact same problem with old fashioned VW Beetle brakes, which are quite similar (single piston master cylinder with remote reservoir, long horizontal frame line, single piston brake cylinders). You can pump the pedal all day with no results. Or just pull the fluid through with a vacuum pump. As soon as the lines have fluid in them you can switch to the pedal if you want.

Bill Robertson
#5939