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Bleeding the Clutch line
Posted: Mon Nov 07, 2016 9:25 pm
by RustyBucket
Thanks to this web site, I was able to track down a valid part number for a replacement hose for my clutch slave cylinder. Now that the hose is replaced, i was hoping to bleed out the line to flush the old gunk out.
Since the reservoir was low on fluid it was removed and the residue cleaned out. I remounted the reservoir and filled it with new DOT3 and got a a brake bleeder pump to draw the new fluid though the system and out the clutch slave bleeder. - so I thought..
The fluid will not pass thorough the line ... It is either blocked wit gunk or I have the pump setup incorrectly?
I have read and re-read the postings on this web site and even got the brake bleeder pump that was mention, but still no luck.
Any suggestions ??
Cam
Re: Bleeding the Clutch line
Posted: Mon Nov 07, 2016 10:32 pm
by Linda
I had the foil top of the brake fluid container fall into the reservoir and stop up the hole....Might want to do a visual check.
Linda
Re: Bleeding the Clutch line
Posted: Mon Nov 07, 2016 10:32 pm
by Linda
Or grit in the bottom of the reservoir too.
Linda
Re: Bleeding the Clutch line
Posted: Tue Nov 08, 2016 6:20 am
by RustyBucket
Linda,
That was one of the first things I checked. But it is spotles except for the new dot3 that I refilled the chamber with after o cleans it out. I may have to blow the line out with low pressure from my compressor. I'm sorry the Datsun didn't spend this much effort to establish functional line when the built the car
Thanks for the suggestion though ..
Cam
Re: Bleeding the Clutch line
Posted: Tue Nov 08, 2016 10:47 am
by RBMann
When you say you removed and cleaned the reservoir I take it you mean the master cylinder on the firewall. The adjustment might be a little off when you remounted it. If the bleed port in the bottom of the reservoir is covered then it will not pass fluid. You should be able to look into the the reservoir and see the seal move past the bleed port as the clutch peddle is depressed.
Re: Bleeding the Clutch line
Posted: Tue Nov 08, 2016 3:48 pm
by RustyBucket

I'm dealing with the clutch. The clutch master is clean. The clutch slave hose is new and installed. The brake bleeder was opened and vacuum pump was connected and I m not able to draw the new dot3 fluid through the line. . It should in theory come charging out with the vacuum on it. I even pulsed the pedal. - no juice. !! Bummer
Re: Bleeding the Clutch line
Posted: Tue Nov 08, 2016 4:05 pm
by fj20spl311
Break the line at the clutch master, the fluid should run out. if that's OK, reattach and break the line at the clutch slave, the fluid should run out...may take a moment or two.
Usually there is no need to bleed a clutch system, many times it just causes a problem.
Re: Bleeding the Clutch line
Posted: Tue Nov 08, 2016 4:18 pm
by RustyBucket
I'll give that a shot. WtH can't hurt
Re: Bleeding the Clutch line
Posted: Tue Nov 08, 2016 8:21 pm
by pebbles
also, you could throw a blanket over the seat, wedge a broom between the seat and the floored pedal, crack the bleeder,,,,
Re: Bleeding the Clutch line
Posted: Tue Nov 08, 2016 8:49 pm
by dbrick
You need to be sure the clutch pedal is letting the cylinder come all the way back or no fluid from the reservoir will get into the cylinder. Bubbles usually come up as the pedal comes to the top and the piston comes back past the hole..
Once you get some flow. you can bleed it like brakes.
Re: Bleeding the Clutch line
Posted: Wed Nov 09, 2016 12:40 pm
by RBMann
RustyBucket wrote:
I'm dealing with the clutch. The clutch master is clean. The clutch slave hose is new and installed. The brake bleeder was opened and vacuum pump was connected and I m not able to draw the new dot3 fluid through the line. . It should in theory come charging out with the vacuum on it. I even pulsed the pedal. - no juice. !! Bummer
I understand you are working on the clutch system. You stated the reservoir was removed and cleaned. If the adjustment on the rod to the clutch peddle is not correct then it will not pass fluid.
dbrick and I are describing the same issue.
Re: Bleeding the Clutch line
Posted: Wed Nov 09, 2016 2:28 pm
by fj20spl311
Clutches are self bleeding! You do not bleed them like brakes.
If you want to use the clutch master to start the fluid flowing, which is some time necessary, you connect your hose to the bleeder and insert it in a container just like you would with your brakes.
The BIG difference is you open the bleeder to release the pressure, but you leave the bleeder OPEN until the pedal is allowed to return to its normal position.
Its only necessary to get the fluid started as its a gravity feed system and the fluid should continue to flow when the bleeder is open.
If you close the bleeder valve with the pedal on the floor, many times as the master piston returns the slave cylinder will retract.
If that happens, and the slave piston doesn't have enough travel -volume- to allow the master cylinder piston to uncover its inlet, the system will not work or flow fluid.
Re: Bleeding the Clutch line
Posted: Wed Nov 09, 2016 2:35 pm
by fj20spl311
DBrink and RBMann are both correct that you need to make sure the inlet is uncovered and not plugged.
If you disconnect the hose at the Clutch Master Cylinder and the inlet is working correctly, fluid will flow out of the cylinder.
Most brake fluid will remove paint!!
Re: Bleeding the Clutch line
Posted: Wed Nov 09, 2016 4:18 pm
by RustyBucket

Thanks for the info. I hope to get to fixing the line this weekend and I'll give your suggestions a shot I'll let you know if I used a bigger hammer or sawsall on the little stinker
Re: Bleeding the Clutch line
Posted: Thu Nov 10, 2016 10:56 pm
by Linda
Not sure on this, so chime in if you guys know, but I "think" that the clutch slave hose has to be in the correct hole, the other is for the bleeder, otherwise does not work correctly.....?? If nothing else works, worth a try.
Linda