| Author | Message | ||
     Christopher Williams Unregistered guest Posted From: 50.84.174.74 |
Hello all, I have an odd brake pump problem that I have not seen before. I have just replaced both brake pumps on my 1977 Shadow II as the #2 pump was getting a bit weak. I also replaced the rubber feed lines, cleaned the fluid reservoir and filters. My problem is that my pumps are not pumping fluid. I have triple checked that I have flow into the pump from the reservoir, and I do. I also removed the pump and ensured the pushrods are moving up and down with engine rotation, and they do. As a last try, I put the pump and outer sleeve into a vise and filled it with fluid, and pumped the piston with a screwdriver, and no pumping action happens. If this were on just one system, I would assume I have a bad pump, but it is on both. I purchased rebuilt pumps from Introcar. Are there any other tests I can perform before I condemn two rebuilt pumps as faulty? Thank you, Christopher Williams (Message approved by david_gore) | ||
| David Gore Moderator Username: david_gore Post Number: 1620 Registered: 4-2003 |
Christopher, Your method of testing the pumps will not indicate if they are functional or not as they need a constant supply of fluid to keep the pump primed. The easiest way to test the pump is to clamp it in a vise with the inlet port facing up. Fill the pump through the inlet with methylated spirits [denatured alcohol] [not DOT brake fluid or RR363 for personal safety reasons]. Gently push the piston in several times to prime the pump making sure the inlet port is kept full of methylated spirit at all times. Put your finger over the discharge port and push the piston in; if the pump is properly assembled, you will feel pressure build up against your finger. If the piston moves and no pressure is felt, reprime the pump as above and then repeat the pressure test. If the pump has been fully primed and no pressure is felt, this most likely means the dished valve disc under the discharge port has been assembled upside down. The dome section should be facing up towards the discharge port. | ||
| Christopher Williams Unregistered guest Posted From: 50.84.174.74 |
Hi David, I did not explain it quite as well as you did, but that is the last test I performed, except I did it the unsafe way and actually used Dot 4 when it was mounted in the vise. I am not feeling pressure build up against my finger or seeing any fluid at all coming from the discharge port when I push the pump piston in. I will check the dished valve disc. I would hope that since I purchased these pumps from Introcar that they were assembled correctly, but I know things do happen. I will check and report back. Thank you for your help. Chris Williams (Message approved by david_gore) | ||
| David Gore Moderator Username: david_gore Post Number: 1622 Registered: 4-2003 |
Hi Chris, The other possibility is the discharge valve disc has been "glued" closed by residual hydraulic fluid that has not been flushed out after testing by the reconditioner and has "gelled" whilst the pump was waiting on the shelf for sale. The hand test may not generate enough pressure to break the "glue" whereas a pump installed and operated by the engine would probably succeed in breaking the bond. It could also damage the surface of the valve disc so I suggest best practice would involve dismantling the pumps to check and clean them before retesting prior to installation. This is why it is also best to use the methylated spirits for testing and flushing the pump as this will not leave a residue that could cause future problems. | ||
| Christopher Williams Unregistered guest Posted From: 50.84.174.74 |
Hi David, I wanted to send my greatest of thanks. I dismantled the hydraulic pump and found that while it was assembled correctly, the non return valve was PACKED full of what appeared to be a mix of old fluid and dissolved rubber. I cleaned the components of all the debris, reassembled and now I have pumping action while the unit is mounted in a vise. I am extremely disappointed that purchasing a "rebuilt" part required this type of tear down to function however, so I will need to speak with my salesman at Introcar about that. Again, thank you very much for your guidance. Chris Williams (Message approved by david_gore) | ||
| David Gore Moderator Username: david_gore Post Number: 1625 Registered: 4-2003 |
Hi Chris, Thanks but it was a guess on my part based on a pump reconditioning I did about 15 years ago after taking over custodial duties on a Corniche afflicted with "flubber disease" [after Walt Disney's Absent-Minded Professor who invented an intriguing green slime] caused by lack of regular changes of RR363. Blocked and subsequently collapsed intake filters in the reservoir with copious amounts of green slime everywhere lead to my undertaking a complete overhaul of the hydraulic system. Just make sure you set the clearance between the push rod head and the top face of the pump mounting flange with a proper depth gauge as per TSD2476 Section E6 pages E33 and E34 when installing the pumps. Having a supply of steel shim stock of varying thicknesses to cut shims is essential if you cannot source OEM shim washers. Removing all the spark plugs makes it easy to rotate the engine to get the pushrod on bottom dead centre to take the necessary measurements. Read the instructions, take care and hasten slowly; the procedure is easier than you think. | ||
| Robert Noel Reddington Experienced User Username: bob_uk Post Number: 16 Registered: 5-2015 |
On my car there is a cover on the bottom of the convertor housing. Under this is the timing marks and access to ring gear. The engine can be turned with a screw drive levering in the ROOT of the teeth on the ring gear. No doubt the carby toots have been removed. To adjust the clearance the valley cam chest cover has to be removed. This gives an excellent view of the cams. Get one brake eccentric on bdc. Mark position on converter with paint. The other brake cam is 360 or one convertor revolution. I can just turn my engine plugs in by pushing the belt tight and pulling on the pas pump pulley. Or remove king lead from middle of dizzy. Note an engine can fire even on open inlet ports if any petrol is around. On the bulk head where ( my car Srh 17768) the hand brake cable runs over a pulley is the starter relay. The red white wire goes to the starter solenoid. The thick brown wire is live. By shorting with long nose pliers the starter can be flicked to move engine. I get close on the starter then fine tune using the belts. Also note that energising the starter will work the ignition system via the ballast resistor and the fuel pumps are connected to the ignition. An aside comment is that we used to put a separate secret switch in the pump feed. My version using a two pole single throw switch also earthed the CB terminal on the ignition coil. Double devious. Bare in mind that the thickness of the chest cover gasket effects the pump clearance. If the original gasket is sound and not torn then a bead of silicon sealer will work fine. The inlet/water manifold to cylinder head gaskets if they come away clean then silicon will work fine. Recommend Wynns black gasket silicon in self propelled can. Press button and the silicon flows in a well controlled bead. Just right. Bolting down spreads the silicon out full width. I like to leave joint just about hand tight allow the silicon to set a bit then wang up to torque. Magic stuff no leaks and beung black it's not obvious like the orange one. Don't over do. Any in an inlet tract will be burnt up and cause no damage ( catylic convertor excepted) However in the coolant bit is not good and a blocked radiator column could result. I have found that a small amount of excess silicon stays firmly joined to the joint. Polish the out side of the brake pump push rods. Mine were disgusting. 400 grit or 000 wire wool. Refit pumps to engine. Leave both pipes loose. Un clamp feed hose and allow a small amount of dot to leak. Tighten pipe. Start engine and when dot leaks from adaptor to output pipe union. Engine off and tighten. Restart engine when lights go out engine off and pump the system down. This will purge air out of the circulatory system. Sometimes the dot will froth a bit. If this happens, just leave for a bit say 1 hour overnight even better. For the bubbles to go. This is one of the reasons dot5 silicon can't be used. Dot5 froths like cola even when pouring it. It would be continually frothed by the pumps. My front pump stopped working and I found the non return full of slimmy corruption. The rear one was clean??. The front stopped working again after a two month lay up. I disconnected the output high pressure pipe and poked a punch down the adaptor hole and pushed the valve down by hand. ( A hammer is verboten) This got the pump to work. I changed the dot from dot 4 to RR363. Since then no problems. Next dot service will be yak363. I think introcar should be made aware and maybe a credit note is possible. I have brought £1000s of parts and every now and then a duff one turns up. I used to return the bits not charging the labour if the bit had been fitted. The manager would then give me even more discount because he has less liability in the parts he sold to me. We did the same when I worked for the cops the discounts are an official secret but I can tell you they were big. All quality oem parts on impress pay when used. Parts not used they take back. No charge. An important safety bit mentioned by Dave Gore. Squirting dot oil is dangerous if you must use safety goggles. Warm water will neutralise dot fast. dot is a poison and getting a squirt in the face is seriously dangerous. So meths Not dot. Once the pump is pumping. Removing the jacket to refit will rid most of the meths from the pump. Small traces of meths will not effect the system. Small is less than 1ml. Or 1/1000 of a litre. Meths evaporates quiet fast. My bro in law Steve nice bloke genuine romany gypsy. Worked as mechanic and using meths he set himself alight. He couldn't see the flames. Fortunately a co worker did see them and hosed him down. When I was an apprentice if someone need a light we used to pour marking fluid which was 50% meth on to a bit on steel then using an electric spark engraver, spark it on fire. The engraver was about 12v and 5amps. Thats how easy meths catches fire. So be care ful with meths and sources of ignition. also injection under the skin is possible. These pumps can develop pressures higher than 3000 psi with ease. Just before the push rod breaks. | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 725 Registered: 5-2012 |
Quote from Bob Or remove king lead from middle of dizzy. Note an engine can fire even on open inlet ports if any petrol is around. That's an essential safety tip. A friend of mine was doing some work on his daughter's Mini. He had removed the carbs, inlet and exhaust manifolds. The engine looked really benign. He then realized he had to get the front wheels onto some ramps, the type you drive up on. But given the engine was now totally disabled how could he get the car onto the ramps. Aha he thought, I'll put the car in first gear and wind it up on the starter motor. Brilliant. So he got in the car, selected first gear and turned the ignition key fully to energize the starter. The car moved forward a few inches whereupon he was greeted with a deafening roar. The car flew up the ramps, overshot, and ended up with the front wheels hanging over the front of the ramps, the wheels spinning uncontrollably with the engine at full revs. All this in less than a second. After changing his trousers, he investigated. He found that on turning the engine, the mechanical fuel pump had squirted petrol through the disconnected fuel pipe, onto the inlet ports. The engine had started at full throttle. The moral of this story - always remove the king lead, even on a stripped down engine. Geoff | ||
| Bob Reddington Unregistered guest Posted From: 92.40.248.62 |
That got the car on the ramps quick. My dad got an non running lawn mower with a snapped off carb. So he squirted petrol into the open port and pulled it and it fired and ran fast for a moment. He then declared it was worth the bother of sorting out the carb. Villiers. Also I have had engines fire and turn simply by turning the dizzy body while timing. The Ghost could be started by turning the engine on the handle to draw fuel and air in then stop turning. And turn on the trembler ignition coil. Hopefully this would fire a cylinder and start the cycle. Also turning engines by hand with ignition on can cause a nasty kick back. Cars are dangerous if one is not careful. (Message approved by david_gore) |
