Yesterday being a public holiday i decided to do some repairs to the tdi. SInce i bought the car i always had brake pedal travel slightly more than other polos that i have driven.
In preparation, last weekend i went to a Ardendorf and got a vacuum pump from them. Apparently it was a one man vacuum pump system. Two bottles Liqui Molly Dot 4 brake fluid from Goldwagon. Should have gotten 3 bottles though.
Before:
Lengthy brake pedal travel with actual stopping felt from around 80% of brake travel.
Pressing the pedal feels like free movement.
Two consecutive pumps and the turbo would start to whine.
Bottle level-Slightly under full.
Fluid last replaced: Unknown
+-170 000km
During:
Discs and pad checks- Visually assessed. Good lifespan remaining on all 4.
Pulled out the intake flexible pipe between the maf sensor and the intake to get to the vacuum hoses. Surveyed the pipes from the tandem pump to their final destinations.
Problem 1 at tandem pump- the plastic fitting on the tandem pump rotates 360 degrees and has an up and down movement approximately 3 to 5 mm. Internal diameter of the vacuum pump bought did not allow me to check for leaks when i rotated the plastic or moved it. It did however hold vacuum when kept steady. Does anyone know if it should have free movement or supposed to be fixed?
Problem 2 at tandem pump- It seems the previous owner tried removing the pipe from the pump and in the process damaged the pipe and covered it with insulation tape. At the same it seemed the pipe was damaged with a screw driver and super glue. This restricted the diameter by half. So now i have a semicircle inside that pipe which i could not break out. I then dusted qbond powder over the butchered pipe and sealed it with the glue as a temp fix. Dried the excess glue and dusted off the excess material to protect the system from contamination. Put the pipe back into the vacuum pump and sealed it with insulation tape just for extra peace of mind.
Checked the rest of the hoses for leaks and signs of perishing. All fine. No crumbling or cracks.
Checked the control box on top of the right shock all. All fine. A tip is to press the two clamps inwards and not pull them out to release the housing. They spring back into place. Refitted the intake pipe.
Removed the 90 degree bend at the egr valve for easy access to the brake fluid bottle. Topped it up to just before overflowing with a funnel made from an Energade bottle. Started at the rear left wheel. I did not remove the wheel as the rim spacing allows me to work while it is on. Pulled out the dust cap. Fitted a number 11 ring spanner over the nut and then fitted the bleeder hose onto the caliper. Attached the hose to the vacuum pump and created vacuum between the the pump and caliper. Opened the nut about 90 degrees and hoped for a steady stream of old junk brake fluid to collect in the bottle supplied. BUT NO. The vacuum dropped so suddenly without bringing any fluid to the bottle. Kept trying different things to have the system bleed out but to no avail. Called a mate and then using the same pipe and bottle supplied with pump,hold and release method started to bleed the system. I removed about 250 to 350ml at the rear left and about 150ml from the rear right and about 100ml from the front wheels. All while checking the reservoir level after a few purges. I rechecked each nut and then replaced the dust caps. The colours of the fluid shocked me. From black to mid green to light green to an almost neon green finish. At least the old stuff is out of the system.
I then checked the egr through the inlet. it had about 1 cm of lining around it. That will be another job for another day. Really hoped i had a scope to check the manifold buildup though. Refitted the boost pipe.
After:
Started the car and had it on idle for a while.
All pipes seemed fine.
Tested the pedal- Travel reduced slightly. The pedal was now firm to press.
Two consecutive pumps and the turbo would not whine. Only after 5 consecutive pumps would it whine.
Test drive- Car brakes much better. No need to stand on the pedal. No difference on the turbo. Emergency stop down Point Road from 140 to 0 made the car pull to the side. I suspect uneven wear on the tyres and brakes. Its a good test road though.
Final thoughts
Buy three bottles instead of two.
Dont buy a vacuum kit unless you want to test the vacuum lines. The long pipes in the test kit collapse easily and the there are not many adaptors to join to the polo pipe sizes.
Rather buy fish tank pipe with a think outer coating to bleed the brakes into a bottle.
Questions:
Does the plastic fitting on the vacuum pump need to move or be fixed?
When on idle. What is the vacuum the pump should be creating?
How to i remove the old vacuum lines and replace with new ones. they seem to be stuck to the non return valves, box and all other points?
How to i upload images of the pipe and the inside of the egr?
Future
Bleed an extra bottle of fluid through the brake system.
Find a set of sportline calipers.
Control arm bushes front and rear, shocks with bearings, ball joints, rack and tie rods, stabiliser links and grease cv joints with new boots also. Considering doing this myself but not sure how difficult it is and what tools are required.
Replace diesel level sensor
Replace rear door locks
Figure out why the boot wont open from the electronic lid control. Opens with the key button though.
Fix horrible sounding noise on the gearbox input shaft or maybe swap to 6 speed.
Cat, egr and stage 1.
tandem pump issues or pipe issues before and after
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- Wheel Whore
- Posts: 49
- Registered for: 6 years 6 months
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- Lieutenant
- Posts: 1626
- Registered for: 7 years 2 months
- Car Make: VW
- Car Model: Polo 9n 1.9 TDI Sportline
- Location: Durban
Re: tandem pump issues or pipe issues before and after
Questions:
*Does the plastic fitting on the vacuum pump need to move or be fixed?
It should rotate
*When on idle. What is the vacuum the pump should be creating?
About 24 in/hg at the vacuum box if I'm not mistaken..
*How to i remove the old vacuum lines and replace with new ones. they seem to be stuck to the non return valves, box and all other points?
Because the pipe going to brake booster is plastic, they seem to be heat shrunk to the 1way valve, so the pipe goes together with the valve. I did have a few cars where the pipes were cut and damaged, I had cut off the damaged areas and joined with a good quality rubber hose - worked as normal for years without issues.
Regarding the pipes at the vacuum box, it takes some twisting and turning to get off, I generally use a small pick/screw driver to pry them out carefully.
How to i upload images of the pipe and the inside of the egr?
Easiest is to download an app called tapatalk, it has a function to upload images, or if u using the Web u have to look for a photo hosting website.
And yes, unfortunately vacuum bleeders don't work on these cars. It's way easier flushing the fluid via the 2 man procedure.
I doubt u have a vacuum issue, if so ur pedal will be hard. And brakes won't be assisted by the booster.
Just to share an experience:
I recently had a problem on a 9n polo where somebody had spaced the master cylinder from the booster (looks like an incorrect booster was used) and because of the spacer, there was excessive brake pedal travel before the brakes start to hold.
On all other vehicles that I have worked on including other polos of the same model, I have never seen any spacers inbetween the master and booster ever
Sent from my EML-L29 using Tapatalk
*Does the plastic fitting on the vacuum pump need to move or be fixed?
It should rotate
*When on idle. What is the vacuum the pump should be creating?
About 24 in/hg at the vacuum box if I'm not mistaken..
*How to i remove the old vacuum lines and replace with new ones. they seem to be stuck to the non return valves, box and all other points?
Because the pipe going to brake booster is plastic, they seem to be heat shrunk to the 1way valve, so the pipe goes together with the valve. I did have a few cars where the pipes were cut and damaged, I had cut off the damaged areas and joined with a good quality rubber hose - worked as normal for years without issues.
Regarding the pipes at the vacuum box, it takes some twisting and turning to get off, I generally use a small pick/screw driver to pry them out carefully.
How to i upload images of the pipe and the inside of the egr?
Easiest is to download an app called tapatalk, it has a function to upload images, or if u using the Web u have to look for a photo hosting website.
And yes, unfortunately vacuum bleeders don't work on these cars. It's way easier flushing the fluid via the 2 man procedure.
I doubt u have a vacuum issue, if so ur pedal will be hard. And brakes won't be assisted by the booster.
Just to share an experience:
I recently had a problem on a 9n polo where somebody had spaced the master cylinder from the booster (looks like an incorrect booster was used) and because of the spacer, there was excessive brake pedal travel before the brakes start to hold.
On all other vehicles that I have worked on including other polos of the same model, I have never seen any spacers inbetween the master and booster ever
Sent from my EML-L29 using Tapatalk
When a car tailgates me, i slow down - then floor it and give them a cloud of diesel smoke to choke on