[Misha]

Front and back window washer doesnt squirt, and no noise is made when i turn them on. So i assume its the pump

Is this the correct part number for my model : 98510-2L100

are they easy enough to replace ? - aka nothing special to know.

[The Gonz]

Working through the compatibility table here:

Amazon.com: KARPAL Windshield Washer Pump 98510-2L100 Compatible With Hyundai Tiburon Kia Sportage : Automotive

it seems to fit if the Elantra GLS 2.0 4-door hatchback petrol is compatible with the i30 Diesel 

Another site lists:

Tucson. Tiburon. With rear wiper. Elantra. Hatchback. Wagon. All.
Replaces:   98510-2C100
VEHICLE FITMENT
Year   Make   Model   Body & Trim   Engine & Transmission
2012   Hyundai   Elantra   GLS, Limited, Touring GLS, Touring SE   1.8L L4 - Gas, 2.0L L4 - Gas
2011   Hyundai   Elantra   GLS, Limited, Touring GLS, Touring SE   1.8L L4 - Gas, 2.0L L4 - Gas
2010   Hyundai   Elantra   Blue, GLS, SE, Touring GLS, Touring SE   2.0L L4 - Gas
2009   Hyundai   Elantra   GLS, SE, Touring   2.0L L4 - Gas

 

This looks promising:

GENUINE BRAND NEW Windshield Washer Pump SUITS HYUNDAI I30 2.0L 2007 - 2012 | eBay 

[Misha]

Thanks @The Gonz , ended up grabbing this from amazon for $35 AUD. Fitted fine with no issues.
Using the rear pump is a little lack luster, reading previous reviews have said similar.

After leaving the water in the tank for ~9 months the water that came out of it was incredibly gross, and growing god knows how many types of algae. 

Fingers crossed the pump lasts a long time.